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633 Cards in this Set
- Front
- Back
Fifth and Sixth best selling drugs
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Abilify and Seroquel; antippsychotics
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Positive symptoms of Schizophrenia
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delusions, hallucinations, inappropriate affect, incoherent speech or thought, odd behavior
gain of function |
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Negative symptoms of Schizophrenia
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affective flattening, alogia, avolition, anhedonia
loss of function |
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affective flattening
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negative symptom; no emotion
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alogia
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negative symptom of Schizophrenia; no speech
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avolition
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no motivation; negative symptom of Schizophrenia
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anhedonia
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no pleasure; negative symptom of schizophrenia
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inappropriate affect
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positive symptom of schizophrenia; inapproriately behaving in regards to emotion; overreacting
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Dopamine Receptor hypothesis of Schizophrenia Version 1
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believed excess transmission at dopamine receptors, so blocking receptors could treat psychosis
antipsychotic drugs increase metabolism of dopamine |
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reserpine
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antipsychotic and anti hypertensive drug
blocks reuptake of dopamine, breaks down vesicles that store dopamine |
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amphetamines
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increase monoamine levels; can induce psychotic symptoms
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Downfalls to Dopamine receptor hypothesis Version 1
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no relation to positive/negative symptoms
no link to genetic and neurodevelopmental deficits no relation to location of abnormalities in living brain |
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Version 2 Dopamine Receptor Hypothesis
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dopamine receptors show differential brain distribution
prefrontal hypodopaminergia and subcortical hyperdopaminergia |
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D1
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dopamine receptor in the cortical region of the brain
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D2
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dopamine receptor in the subcortical region of the brain
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Downfalls of Version 2 hypothesis
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no relation to positive/negative symptoms
no direct evidence |
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Version 3 Dopamine Receptor Hypothesis
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striatal dopamine dysregulation
this alters the appraisal of stimuli which induces psychosis |
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NT's linked to Schizophrenia
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serotonin, glutamate, NMDA receptors
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PCP and Ketamine
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anesthetics that induce negative symptoms and cognitive dysfunction due to schizophrenia
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Glutamate Hypothesis for Schizophrenia
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symptoms might reflect dysfunction or dysregulation of NMDA receptors and neurotransmission
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Brain damage in Schizophrenia
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global atrophy of grey matter
ventricular enlargement alterations in fronto-temporal regions volume decrease in temporal structures: superior temporal gyrus, and inferior frontal cortex |
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Affective (Mood) Disorders
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Depression
Mania Biopolar Unipolar |
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Neurochemical imbalance theory of depression
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synthesis and secretion of norepinephrine and serotonin
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Monoamine theory of depression
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impairment in central monoaminergic function
serotonin, norepinephrine, and dopamine disruption depression associated with underactivity of serotonergic and noradrenergic synapses |
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Meds for monoamine theory
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agonists of serotonin, norepinephrine, or both
Norepinephrine and serotonin receptors have been found to be more numerous in the brains of deceased clinically depressed individuals (up-regulation) |
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Deficiency of norepinephrine
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can result in depressed mood
low levels can= depression NE projects to frontal cortex and limbic hypothalamus |
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Deficiency of serotonin
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also called 5-HT
Projects to frontal cortex, basla ganglia (limbic regions), and hypothalamus |
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Drugs used to treat Depression (MDD)
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Monoamine oxidase inhibitors
Tricyclic antidepressants selective monoamine-repuptake inhibitors mood stabilizers |
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Monoamine oxidase inhibitors
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Example: Iproniazid (developed for treatment of TB)
Monoamine agonist increases levels of monoamines by inhibiting the activity of monoamine oxidase (MAO) |
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side effects of monoamine oxidase inhibitors
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cheese effect: cheese, wine, and other food containing amine tyramine
elevates blood pressure |
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Tricyclic antidepressants
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Example: Imipramine
Blocks reuptake of 5HT and NE safer than MAO inhibitors |
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Selective Monoamine-reuptake Inhibitors
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SSRIs
serotonin agonists block reuptake of serotonin from synapses increases activation of serotonin receptors Other examples: Fluoxetine, Paxil, Zoloft few side effects |
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Selective Norepinephrine Reuptake Inhibitors
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SNRIs
Reboxetine: example |
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Wellbutrin
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blocks reuptake of more than one monoamine NT
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Sleep Alterations in Depression
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older antidepressants disrupted REM sleep
some enhance REM sleep 5-HT modulates sleep and wakefulness |
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Pathophysiology of Depression
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adaptation of plasticity of neural systems
decrease in number of length of branch points of apical dendrites of CA3 neurons in hippocampus decrease in plasticity in depression and chronic stress |
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Glucocorticoids and Depression
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increase levels of basal cortisol
corticosteroids influence NT, CORT secretion likely regulated by monoamines Hippocampus and prefrontal cortex have high levels of CORT receptors |
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HPA axis
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hypothalamo-pituitary adrenal axis
associated with glucocorticoids Hypothalamus secretes CRF (corticotropin releasing factor) which targets the anterior pituitary, which secretes ACTH (adrenocorticatropic hormone) which targets the adrenal cortex and that secretes GCORT patients with MDD have high levels of CORT |
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Other effects of depression
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Impairs neuroplasticity
hippocampal volume reduction, HPA axis, and depression link? Hippocampal atrophy could result i further neuroendocrine dysfunction, and hence a run-away system |
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HPA overactivity
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leads to increased sympathetic tone, which promotes release of cyto cines from macrophages
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Kindling hypothesis
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depressive episodes become more easily triggered over time
as the number of depressive episodes increases, future episodes predicted more by the number of prior episodes rather than life stress |
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Neuropathology seen in Depression
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abnormalities in prefrontal cortex, basal ganglia, hippocampus, thalamus, cerebellum, and temporal lobe
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Prefrontal cortex abnormalities in depression
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medial PFC size reduced
reduction in number of glial cells increase in activity posterior orbital PFC, amygdala, and anterior cingulate cortex |
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Treatments for treatment-resistant cases
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Deep Brain stimulation
Electroconvulsive Therapy |
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Deep Brain stimulation
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experimental
electrical stimulation of the medial PFC and anterior cingulate 60% showed improvement |
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Electroconvulsive Therapy
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intentionally triggering a brief seizure
changes neurochemistry 2-3 times a week for a couple of weeks memory loss right around that event |
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Mood stabilizers
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antidepressants can trigger bouts of mania, but these do not
Lithium act on signal transduction mechanism trigger long-term changes in neuronal signaling patters that account for its prophylactic properties |
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Anxiety Disorders
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all associated with anxiety and physiological stress reactions
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symptoms of Anxiety Disorders
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tachycardia, hypertension, breathing difficulties, nausea, high glucocorticoid levels
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Etiology
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genetic component
experiences |
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Anxiolytics (anti-anxiety)
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Benzodiazepines
Serotonin agonists |
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Benzodiazepines
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Valium
agonistic action at GABA-A receptors sedation, ataxia, nausea, withdrawal reaction that induces rebound anxiety good for short-term use |
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Serotonin agonists
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Buspirone
Selective agonists effects at 5-HT1A receptor no ataxia and sedation |
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Anxiety Disorders and Depression
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show comorbidity
both involve heightened emotional response to stress SSRIs are often effective against anxiety disorder |
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Neural bases of anxiety disorders
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possible role of GABAergic and serotonergic transmission
Brain areas involved and affected: amygdala (heightened activity) anterior cingulate cortex |
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Reticular theory
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nervous tissue is a continuous web of unbroken network and information can blow between the this web; Golgi's proposal
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Neuron Doctrine
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each neuron is an independent unit, the nervous system is made up of nervous systems
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Unipolar neuron
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the cell body is set off from the trunk of the axon
single branch coming from cell body which extends in two directions find these in touch receptors sensory receptor |
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Bipolar neuron
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cell body isn't off set, still has two extensions
important in vision and olfaction sensory systems |
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multipolar neuron
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what most neurons of the vertebrate brain are
single axon; many dendrites |
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multipolar interneuron
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really small axon that has no myelin
found in the spinal cord point to point communicator |
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dendrites
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specialized input zones
shorter than axons many in one neuron |
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axons
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specialized output zones
range from nonexistent to several meters long axon hillock present |
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axon hillock
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where an action potential is initiated
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synapse
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at the terminal button; where NT are able to bind to the dendrites
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presynaptic membrane
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synaptic vesicles contained in presynaptic axon terminal; contain NT
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postsynaptic membrane
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contains receptors for NT
where the soma and the dendrites are |
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axonal transport
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the process by which the materials and nutrients move across the axon
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anterograde transport
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movement of materials from the soma toward the terminal button
kinesin is motor protein involved in this Functions to supply nerve terminal with necessary components |
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retrograde transport
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movement of any material from the axon terminal back toward the soma
dymine is the motor protein involved |
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recycling
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type of retrograde transport
return of "used up" material from the nerve terminal to the soma for degradation or reuse |
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signaling
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type of retrograde transport
postsynaptic messengers or regulatory substances terminal button can give back info to the soma about what is going on |
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Oligodendrocytes
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glia cell
in the CNS can myelinate multiple axons of multiple cells at one time faster communication speed because of myelin |
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schwann cells
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located in the PNS
can only myelinate one part of one cell |
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Astrocytes
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in the CNS
star-shaped connect brain to vascular system buffer ion concentrations in extracellular spaces involved in NT uptake |
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microglia
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small glia cells
clean up dead or injured cells in the brain |
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ependymal
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lines the ventricles of the brain and produces the CSF
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Golgi staining
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looks at dendritic spines
more spines means more complexity of information |
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Nissl stain
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stain cell bodies
can't see as much detail |
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Myelin stain
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stain myelin
useful to look at axon pathways |
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Electron microscopy
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get very high resolution
can look at microtubules, synapses, or layers of myelin wrapping |
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anterior
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also called rostral
front of the nose |
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posterior
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also called caudal
back of the head |
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dorsal
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top of the head
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ventral
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bottom of the head
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ipsilateral
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same side
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contralateral
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opposite side
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bilateral
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what most structures of the brain are
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medial
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towards the center
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lateral
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towards the side
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proximal
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close to
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distal
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away from
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afferent
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towards the reference point
towards the brain |
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efferent
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away from the reference point
away from the brain |
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sagittal cross section
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lateral sectioning
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coronal cross section
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cutting like a loaf of bread
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horizontal cross section
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sectioning it horizontally
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Peripheral Nervous System
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Contains the somatic nervous system
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Sensory nerves
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afferent neurons
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Motor nerves
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efferent neurons
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spinal nerves
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innovatie musculature within that region
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ventral roots
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carry motor information
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dorsal roots
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carry sensory information
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Autonomic nervous system
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sympathetic nervous system and parasympathetic nervous system
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Central Nervous system
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brain and spinal cord
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gray matter
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contains interneurons
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white matter
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contains axons
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spinal cord
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white matter on the outside, grey matter on the inside
central canal contains the CSF |
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The Meninges
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dura mater
arachnoid pia mater |
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dura mater
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outter most; tough tissue of brain and spinal cord
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arachnoid
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web-like; contains CSF and arachnoid villa
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pia mater
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inner most; delicate
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Cerebrospinal fluid (CSF)
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contained in the ventricular system
produced by the choroid plexus and ependymal cells |
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Lateral ventricles
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ventricles 1&2
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Ventricles
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all connected to each other. where the CSF is located
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Hydrocephalus
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defect in how the CSF leaves the brain, so it builds up. Ventricles enlarge, and the cortical tissue gets smooshed out.
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Olfactory nerve
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cranial nerve #1
function: sensory; smell |
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Optic nerve
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cranial nerve #2
function: sensory; vision |
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oculomotor nerve
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cranial nerve #3
function: motor and sensory; eye movement and pupillary constriction; sensory signals from certain eye muscles |
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trochlear nerve
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cranial nerve #4
function: motor and sensory; eye movement; sensory signals from certain eye muscles |
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trigeminal nerve
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cranial nerve #5
function: sensory and motor; facial sensations; chewing |
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abducens
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cranial nerve #6
function: motor and sensory; eye movement; sensory signals from certain eye muscles |
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facial nerve
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cranial nerve #7
function: sensory and motor; taste from anterior 2/3 of tongue facial expression, secretion of tears, salivation, cranial blood vessel dilation |
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auditory-vestibular nerve
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cranial nerve #8
function: sensory; audition; sensory signals from the organs of balance in the inner ear |
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Glossopharyngeal nerve
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cranial nerve #9
function: sensory and motor; taste from posterior 1/3 of tongue; salivation, swallowing |
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Vagus nerve
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cranial nerve #10
function: sensory and motor; sensations from abdominal and thoracic organs; control over abdominal and thoracic organs and muscles of the throat |
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Spinal Accessory Nerve
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Cranial nerve #11
function: motor and sensory; movement of neck, shoulders, and head; sensory signals from the muscles of the neck |
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hypoglossal nerve
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cranial nerve #12
function: motor and sensory; tongue movements; sensory signals from tongue muscles |
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Choroid plexus
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lines the ventricles and is continuously secreting CSF
constituted by the ependymal cells |
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functions of CSF
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mechanical stability
chemical transport removing large molecules regulation of chemical environment |
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foramen of luschka and foramen of magendia
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openings in the fourth ventricle where the CSF flows in and out
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Lumbar puncture
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spinal needles is inserted in between the 3rd and 4th lumbar vertebrae
taps into central canal Examines: proteins glucose mononuclear cells CSF pressure |
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Abnormalities seen in Lumbar puncture
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blood- brains tumors/ subarachnoid hemorrhage
increased inflammatory cells- syphilis/brain tumors increased protein- myelin fragments, myelin basic protein |
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internal carotid arteries
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artery that supplies blood to the brain
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vertebral artery
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supplies blood to the brain
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Circle of Willis
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where the basilar artery joins the carotid artery in a circular shape
provides a safety mechanism |
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blood brain barrier
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functions to protect the brain from toxins and infections
can make drug delivery to the brain more difficult |
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Forebrain
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contains the telencephalon and the diencephalon
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Midbrain
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contains the mesencephalon
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hindbrain and brain stem
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contains the metencephalon and the myelencephalon
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cerebral cortex
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means "bark"
forms the outer surface of the cerebral hemispheres grey matter outside, white matter inside primarily composed of cell bodies |
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sulci
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small grooves
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fissures
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large grooves
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longitudinal fissure
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runs along the two cerebral hemispheres
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gyri
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bulges in cortex
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columnar organization
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columns are mini processing units
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paramital neuron
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located in regions 4 and 5, has one long axon and many basal dendrites
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Von Economo neuron
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found in humans, great apes, elephants, and dolphins
related to emotional and social feelings complex social behavior |
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Frontal lobe
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anterior to the central sulcus and dorsal-medial to the lateral fissure
includes the primary motor cortex contains prefrontal cortex |
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prefrontal cortex
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associated with executive function
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central sulcus
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important boundary that separates the frontal lobe from the parietal lobe
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Sylvian fissure (lateral fissure)
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separates the frontal lobe form the temporal lobe
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Parietal lobe
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behind the central sulcus and in front of the occipital lobe, and dorsal-medial to the lateral fissure
includes the primary somatosensory cortex auditory and visual info |
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temporal lobe
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below lateral fissure and in front of occipital lobe
includes the primary auditory cortex |
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occipital lobe
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includes primary visual cortes and secondary visual cortex
below the parietal and temporal lobes |
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Corpus Callosum
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band of white matter fibers
seen through midsagittal section very organized communicates info from one hemisphere to the other |
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anterior commissure
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toward the front of the brain
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posterior commissure
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toward the hindbrain
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Limbic system
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associated with emotion
contains the hippocampus, amygdala, olfactory bulbs, and cingulate gyrus |
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hippocampus
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functions in memory
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amygdala
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involved in detection of stimlui that can be perceived as danger or a threat
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olfacotry bulbs
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cranial nerve #1
initial input of olfactory stimuli most primitive sense |
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cingulate gyrus
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band superior to the corpus callosum
emotion responses involved in the processing of the info sent by emotions |
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basal ganglia
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collection of subcortical nuclei that lie just under the anterior aspect of the lateral ventricles
consists of: globus pallidus, caudate nucleus, putamen, and the substantia nigra |
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Diencephalon
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in the forebrain
contains the thalamus and hypothalamus contains nuclei that receive sensory info and transmit it to the cortex sensory relay station all senses except parts of olfaction go through the thalamus |
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Hypothalamus
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nuclei involved in integration of species typical behaviors, control of the autonomic nervous system and pituitary
3 f's: feeding, fighting, and sexual behavior |
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Mesencephalon
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located in the midbrain
contains the tectum and the tegmentum |
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tectum
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dorsal portion of midbrain
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superior and inferior colliculi
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involved in visual and auditory systems; in the tectum
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superior colliculi
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involved in visual systems
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inferior colliculi
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involved in auditory systems
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Tegmentum
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portion of midbrain located under the tectum and contains:
rostral end of reticular formation perlaqueductal gray red nucleus substantia nigra ventral tegmental area |
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Metencephalon
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in the hindbrain
contains: pons cerebellum |
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pons
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involved in the control of sleep and arousal
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cerebellum
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involved in motor control
timing, tension switching |
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Myelencephalon
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contains the medulla oblongata
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medulla oblongata
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most caudal portion of brain
rostral to spinal cord contains part of the reticular formation involved in respiration |
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Neuronal signaling
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1. receives signal (chemical or physical)
2. signal causes ionic fluctuations in the neuron's plasma membrane 3. creates an electrical current flow in the neuron 4. current flow travels down the axon 5. when current reaches terminal button, NTs are released into synapse |
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Axodendritic synape
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most common
axons synapse onto dendritic spines of the postsynaptic neuron |
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Types of synapses
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axon on axons
dendrites on dendrites axodendritic |
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Membrane Potential
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the difference in electrical charge from the distribution of positively and negatively charged ions between the inside and outside of a cell
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Diffusion
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ions want to flow from an area of high concetration to an area of low concentration
imbalance= concentration gradient |
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selective permeability
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membrane can be impermeable to both ions
membrane can select for which ion can cross the membrane |
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electrical potential
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difference in charges across the membrane
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Resting Membrane Potential
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neuronal membrane is mostly impermeable; responsible for maintaining the resting potential
selectively permeable (not equally) to K+, Cl-, and Na+ More Na+ on the outside, more K+ on the inside, and more Cl- on the outside |
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Voltage difference
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difference between the intracellular fluid and the extracellular space
at resting potential it is -70mV |
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Channel
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passive
doesn't require any active support by the neuron to have things move across |
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Ion pump
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active
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Sodium- Potassium Pump
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uses ATP to move 3 Na+ out and bring in 2 K+
uses a lot of energy where most of the neurons energy goes to |
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Non-gated channels
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permit the passage of Na+ in and K+ out. More K+ leaks out than Na+ leaks in because the membrane is more permeable to K+
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Mechano-sensitive channels
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affected by distortions in the membrane around it
convert external mechanical forces into signals |
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Voltage-sensitive channels
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Whether the gate is open/closed is determined by the voltage is around it
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Ligand-sensitive channels
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affected by chemical agents
found on dendrites in the postsynaptic cells |
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Graded potentials
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small voltage fluctuations
restricted to portion of axon where ion concentrations change |
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hyperpolarization
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due to an efflux of K+ or influx of Cl- voltage inside axon becomes more negative
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Depolarization
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due to an influx of Na+, voltage inside axon becomes more positive
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Threshold
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about -65mV
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threshold of excitation
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the point of voltage that will result in an action potential
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action potential
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brief, large reversal in the polarity of an axon's membrane
all sodium voltage gated channels open intracellular side becomes positive then reverses again hyperpolarizes then restores to resting potential |
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Hodgin-Huxley cycle
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Depolarization of membrane => opens Na+ channels => Na+ flows into neuro=> depolarization of membrane
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absolute refractory period
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when it starts to come down to restore itself
membrane hits 40mV, all the Na+ voltage-gated channels close and K+ voltage-gated channels open |
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Myelinated axons
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nodes of ranvier contain the voltage-gated Na+ channels
allows Na+ to rush in sodium potential jumps down the length of the axon much faster |
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postsynaptic potentials
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graded potentials causing a depolarization or hyperpolarization
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Excitatory postsynaptic potential (EPSP)
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brief depolarization of nueron membrane
more likely to produce action potential |
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Inhibitory postsynaptic potential (IPSP)
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brief hyper polarization of neuron membrane
less likely to produce an action potential |
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Integration of PSPs and Generation of an AP
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One EPSP typically will not cause a neuron to fire need summation
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integration
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adding or combining a number of individual signals into one overall signal
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spatial summation
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integration of events happening at different places but at the same time
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temporal summation
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integration of events happening at different times
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Loewi's classic experiment
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have a donor heart and recipient heart
stimulate donor heart and heart rate slows down removed fluid sample from donor and put in recipient heart caused the heart rate of recipient heart to slow down secreted vagusstoff (acetylcholine) |
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Synaptic transmission in 4 steps
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1. NT synthesized and stored in axon terminal
2. NT release 3. Receptor-site activation 4. NT deactivation |
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Step 1 of synaptic transmission
NT synthesized and stored in axon terminal |
transporters pump substances across the cell membrane
requires substances acquired from the blood supply synthesized and packaged all down the axon terminal |
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NT synthesized in soma
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transported on microtubules to axon terminal (anterograde transport)
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Step 2: NT release
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In response to Action potential, NT released across the membrane by exocytosis
Ca2+ channels open Ca2+ bind to protein calmodulin complex binds to vesicles, inducing some vesicles to bind to presynaptic membrane docking complex brings them together and they fuse |
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Step 3: receptor-site activation
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Nt binds to receptor embedded in postsynaptic membrane
EPSP or IPSP initiate other chemical reactions that modulate either of the previous effects |
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autoreceptor
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self-receptor in neural membrane that responds to the transmitter released by the neuron
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Ionotropic receptors
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associated with ligand-activated ion channels
fast communication NT binds and ion channel opens or closes, causing a PSP Na+ channels are opened, EPSP K+ channels are opened, IPSP |
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Metabotropic receptors
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associated with signal proteins and G proteins
NT messenger binds G protein subunit breaks away Ion channel opens/ closes OR 2nd messenger is synthesized slower, longer-lasting found in learning membrane areas |
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long-term potentiation
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the neurological changes that happen while learning
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Quantum
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quantity that produces a just observable change in postsynaptic potential
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Number of quanta factors
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amount of Ca2+ that enters the axon terminal
number of vesicles docked at the membrane |
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Step 4: NT deactivation
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Reuptake or Enzymatic degradation
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Reuptake
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transporter pumps in the presynaptic that bring the NTs back up into the button of the presynaptic neuron; could grab the NT before it binds to receptor
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Enzymatic degradation
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deactivating enzyme that is specific to the NT attach and deactivate the NT by breaking it down
ONLY FOR ACETYLCHOLINE |
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Amino Acid NTs
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usually found at fast-acting directed synapses in the CNS
Glutamate GABA Aspartate and glycine |
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Glutamate
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most widespread excitatory NT in the brain
two types of receptors: AMPA and NMDA activated by MSG |
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AMPA receptor
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ionotropic receptor of Glutamate
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NMDA receptor
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metabotropic receptor of Glutamate
important in memory |
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GABA
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widespread inhibitory NT in brain and spinal cord
opens chloride channels and works on K+ channels |
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Glycine
|
widespread in spinal cord
inhibitory NT lower parts of the brain; hindbrain regions important in locomotive behavior if blocked, see continuous contraction tetnis can block glycine |
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Monoamines
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found in pathways essential for sensory and motor functions; cognitive functions
not as many specific and limited neural pathways have huge effects on cognitive and motor function |
|
Catecholamines
|
synthesized from tyrosine
includes: dopamine norepinephrine epinephrine |
|
dopamine
|
can produce excitatory and inhibitory postsynaptic potential
Two main pathways: mesolimbocortical pathway mesostriatal pathway involved in mood regulation inbalances in schizophrenia |
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mesolimbocortical pathway
|
originates in ventral tegmental area to nucleus accumbens, cortex, and hippocampus
feeds into limbic system structures |
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mesostriatal pathway
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substantia nigra to striatum
important in initiation of movement |
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norepinephrine
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noradrenergic pathways:
locus coeruleus lateral tegmental area related in regulation of mood and arousal (CNS) in the sympathetic nervous system has an excitatory effect |
|
Locus coeruleus
|
In the region of the pons to the hippocampus, basal ganglia, and cortex.
Involved in alertness and awakeness |
|
lateral tegmental area
|
projects to the spinal cord, pons, and cerebellum
|
|
epinephrine
|
also known as adrenaline
synthesized from norepinephrine; location tends to be in adrenal medulla (adrenal gland) also a hormone in brain, it's NT released from adrenal medulla in response to stress |
|
Indolamines
|
synthesized from tryptophan
includes: serotonin |
|
serotonin
|
synthesized by the raphe nuclei
pathways: projections to hippocampus, spinal cord, cerebellum mesencephalic seroteonergic cells project to thalamus, hypothalamus, basal ganglia, and cortex involved in eating, regulation of sleep and arousal, and also involved in regulation of pain and mood. regulates REM sleep and dreams LSD acts on serotonin receptors |
|
Acethylcholine
|
Acetyl group + choline
Excitatory effect on skeletal muscles inhibitory effect on muscle fibers of the heart involved in initiation of REM sleep Pathways: peduculopontine basal forebrain only NT destroyed by enzyme Receptors: nicotinic muscarinic |
|
Peduculopontine pathway
|
cholinergic pathway in brain
nucleus and laterodorsal tegmental nucleus |
|
Basal Forebrain pathway
|
cholinergic pathway in brain
nucleus basalis, medial septal nucleus, and nucleus of diagonal band |
|
nicotinic receptor
|
acteylcholinergic receptor
ionotropic, excitatory muscle fibers only |
|
muscarinic receptor
|
acetylcholinergic receptor
metabotropic, excitatory or inhibitory slower and longer lasting CNS contains mostly muscarinic receptors |
|
Unconventional NTs
|
soluble gases
Endocannabinoids |
|
soluble gases
|
unconventional NT
nitric oxide and carbon monoxide retrograde transmission diffuse through cell walls |
|
endocannabinoids
|
anandamide is one of the two known
|
|
Neuropeptides
|
large molecules
Substance P, Neuropeptide Y Endorphins Endogenous opioids |
|
Substance P
|
involved in pain reception
|
|
Neuropeptide Y
|
involved in circadian rhythm and eating patterns
|
|
Endogenous opioids
|
body's natural pain relievers
produce analgesia |
|
mass action
|
whole brain is involved in all functions
|
|
localization of function
|
means specific areas of the brain were involved in certain functions
|
|
Broca's area
|
third convolution of the left frontal lobe
|
|
Neuropsychological testing of humans
|
very time intensive
|
|
Finger tapping frequency
|
motor tasks test
used in parkinson disease |
|
peg board
|
insert the pegs and then told to retrieve them out and it is timed. Then do it with other hand.
Motor task test used for Parkinson's |
|
Sequential finger learning
|
used for Parkinson's
motor task test |
|
WAIS
|
intelligence test
memory, language, language lateralization |
|
Wisconsin card sort task
|
memory (short term/long term, elicit/implicit)
language frontal lobe function people with frontal lobe lesions adapt poorly to rule changes in this test |
|
Open-field test
|
three measures of emotionality:
inactivity thigmotaxis (don't venture from the walls of the enclosure- hesitant to go into open space) defecation (number of bowels) |
|
Aggression and defense analysis of species-common behavior
|
predatory aggression
maternal aggression sexual aggression |
|
Sexual behavior: analysis of species-common behavior
|
Female:
lordosis lordosis quotient: proportion of mounts that produce lordosis Males: number of mounts to intermission number of intermissions to ejaculation time to reinitiate mounting after ejaculation |
|
Static Imaging Techniques
|
CT
MRI |
|
CT (computerized tomography)
|
Narrow x-ray beam passed through the brain at many different angles
Images combined to create 3D image of brain Not good resolution, a bit fuzzy Not used for research purposes more rapidly triage patients requiring emergency surgery |
|
MRI (magnetic resonance imaging)
|
hydrogen atoms behave like spinning bar magnets in the presence of magnetic field
non ionizing radiation density differences in hydrogen atoms in different regions in magnetic field, hydrogen atoms line up in parallel radio pulses applied structural MRI preferred in brain tumors and infection |
|
Dynamic Brain Imaging
|
PET
fMRI Resting State fMRI Transcranial Magnetic Stimulation (TMS) |
|
PET
|
positron emision tomography
small amount of radioactively labeled substance injected into subject active areas of the brain use more blood and thus have more radioactive labels look at distribution of what areas are more active than the others in the brain |
|
fMRI
|
function MRI
increases in functional activity of brain, increase in blood flow to those regions Blood oxygen level dependent Temporal resolution may not be very accurate compared to structural MRI must be motionless and alert no radiation measures changes in brain activity in more or less real time compared to PET |
|
Resting state MRI
|
mesures brain activity when you are at rest
Shows high levels of brain activity when you are not task engaged, but when you become task engaged, see a decrease in this. |
|
Transcranial Magnetic Stimulation (TMS)
|
becoming one of the most important research tools
|
|
stereotaxic surgery
|
means by which experimental devices are precisely positioned in the depths of the brain. An atlas is required to provide directions to the target site and an instrument for getting there.
place an experimental device in the brain in a precise and accurate location can administer drug can inject a chemical that can cause a lesion |
|
Three principles of the sensorimotor function
|
1. Hierarchically organized
2. Motor output is guided by sensory input 3. Learning changes the nature and locus of sensorimotor control |
|
Functional segregation
|
each level of the hierarchy tends to be composed of different neural structures, each of which performs a different function
|
|
Ballistic movements
|
brief, all-or-none, high speed movements
aren't influenced by sensory feedback |
|
proprioception
|
knowing where your arms and legs are and being aware of surroundings
|
|
Proprioceptive disorder
|
no movement is automatic. Have to think every little step through in order to move
|
|
Initial stages of motor learning
|
each individual response is under conscious control
|
|
After practicing motor learning
|
responses become organized into continuous integrated sequences of action
|
|
Hierarchy
|
1. Association cortex
2. Secondary motor Cortex 3. primary motor cortex 4. brain stem nuclei 5. spinal motor circuits |
|
Association cortex
|
contains the posterior parietal association cortex and dorsolateral prefrontal association cortex
|
|
parietal association cortex
|
integrates info about body part location and external objects
receives visual, auditory, and somatosensory info from visual cortex auditory cortex, and somatosensory cortex directs behavior by providing spatial info and directing attention Outputs: motor cortex dorsolateral prefrontal cortex secondary motor cortex frontal eye field conscious intention and motor awareness arise from increased parietal activity BEFORE movement execution |
|
frontal eye field
|
small area of prefrontal cortex that controls eye movements
|
|
apraxia
|
disorder of voluntary movement
only evident when instructed to perform an action damage to the left posterior parietal cortex |
|
contralateral neglect
|
unable to respond to stimuli contralateral to the side of the lesion
seen with large lesions on the right |
|
Dorsolateral prefrontal association cortex
|
input: posterior parietal cortex
output: secondary motor cortex, primary motor cortex, and frontal eye field evaluation of external stimuli and initiation of voluntary reactions |
|
Secondary Motor Cortex
|
Input: association cortex
areas included: Supplementary motor area (SMA and preSMA) premotor area cingulate motor areas output: primary motor cortex involved in programming patterns of movements in response to input from dorsolateral prefrontal cortex active when imagining/planning movements |
|
Primary Motor Cortex
|
Located in precentral gyrus of frontal lobe
Major point of convergence of cortical sensorimotor signals Major point of departure of signals from cortex somatotopic- more cortex devoted to body parts organized motor humunculus Function: initiating body movements |
|
Motor humunculus
|
control of hands
|
|
stereognosis
|
recognizing by touch
interplay of sensory and motor systems |
|
PMC lesions
|
disrupt ability to move one body part independently of another
|
|
astereognosia
|
not being able to move hands
|
|
Brain Stem Motor Nuclei
|
controls muscles of head and neck
contains: midbrain pons caudal pons ponto-medullary junction medulla cervical cord reticular formation |
|
reticular formation
|
In medulla and pons:
important in modulation respiration, heart rate, and blood pressure In rostral pons and midbrains: critical for maintenance of consciousness |
|
reticular nuclei
|
important for mediating eye movement
|
|
Spinal motoneurons
|
All muscles outside of head and neck
sends commands to spinal cord => muscles pathways: 2 dorsolateral: corticospinal corticorubrospinal 2 ventromedial: corticospinal cortico-brainstem-spinal tract |
|
Corticospinal pathway
|
the direct pathway for dorsolateral and ventromedial pathways of the spinal motoneurons
|
|
corticorubrospinal
|
indirect dorsolateral pathway of spinal motoneurons
|
|
cortico-brainstem-spinal tract
|
indirect ventromedial pathway of the spinal motoneurons
|
|
Cerebellum
|
input:
primary and secondary motor cortex brain stem nuclei somatosensory and vestibular systems involved in fine-tuning and motor learning |
|
layers of the cerebellum
|
molecular layer
purkinje cell layer granular layer |
|
molecular layer of the cerebellum
|
outter most
axons for the granular cells; few cell bodies dendrites of purkinje cells |
|
purkinje cell layer
|
middle layer
output cells output of the cerebellum |
|
granular layer
|
inner most layer of cerebellum
dense cell bodies processing cells- most processing done here |
|
Cerebellar loops
|
prefrontal loop
motor loop |
|
prefrontal loop of cerebellum
|
dentate nucleus=> prefrontal regions of cortex => pontine nucleus => cerebellar cortex
|
|
pontine nucleus
|
part of the pons involved in motor activity
|
|
dentate nucleus
|
within cerebellar hemisphere
|
|
damage to cerebellum
|
movement deficits of timing, force, range, and direction
impairment of equilibrium during walking deficits in voluntary eye movement problems in motor learning |
|
Basal Ganglia
|
collection of nuclei
receives cortical input and send output back via thalamus modulate motor output and cognitive functions involved in parkinson's, Huntington's, OCD, ADHD, and schizophrenia |
|
brake hypothesis
|
puts on the brake or releases the break
example: sitting down regulated by basal ganglia |
|
Direct pathway of basal ganglia
|
Glutamatergic excitation from cortex to neostriatum
then GABAergic inhibition from neostriatum to GPi |
|
Substantia nigra
|
SNpr and SNpc
|
|
SNpr
|
substantia nigra pars reticulate
eye movements |
|
SNpc
|
substantia nigra pars compacta
large DA-containing cells |
|
Parkinson's Disease
|
resting tremor that's lost during intended movements
difficulty initiating movements 60% neuron loss DA neurons degenerate loss DA results in decrease in striatal activity, so less inhibition of GP increasing GP reduces firing of thalamus, which decreases excitatory input to motor cortex results in hypokinesis |
|
hypokinesis
|
diminished motor function
|
|
MPPP
|
super demerol
found through teenagers doing drug that came in with parkisonian symptoms synthetic opioid; like heroid |
|
MPTP
|
converted to MPP+ by monoamine oxidase
MPP+ is toxic to DA neurons of substantia nigra |
|
Riluzole
|
blocks nMDA receptors
|
|
Baclofen
|
eases the pain of muscles spasms
|
|
Cerebellar ataxia
|
difficulty with eye movements
can't complete standard sobriety tests balance is off |
|
Indirect pathway of Basal Ganglia
|
cortex=> neostriatum => globus pallidus external => subthalamic nucleus => globus pallidus internal => thalamus => cortex
Globus pallidus inhibited then wil not inhibit subthalamic nucleus; inhibits thalamus so not excitation of cortex GABAergic inhibition from striatum to GPe GPe inhibited => subthalmic nucleus has glutamatergic excitation to GPi thalamus inhibited so no excitation of cortex |
|
Huntington's chorea
|
spontaneous, disruptive movements, uncontrolled
inherited, progressive neurodegenerative disorder genetic mutation in coding for "Huntington" protein striatal neurons projecting to and inhibiting GPe degenerate GPe isn't inhibited, so it fires. then inhibits subthalamic nucleus from exciting GPi, which then fires less. Thalamus not inhibited by GPi and fires Results in thalamus exciting motor cortex => hyperkinesia |
|
hyperkinesia
|
uncontrollable spontaneous movement
|
|
Plasticity of the brain
|
changeable; ability to adapt to experience
|
|
Neurogenesis
|
growth of new neurons; occurs in adults as well; does decline with age
|
|
Phases of development
|
1. induction of neural plate
2. neural proliferation 3. migration and aggregation 4. axon growth and synapse formation 5. neuron death and synapse rearrangement 6. synaptogenesis 7. myelination |
|
Induction of neural plate
|
A path of tissue on the dorsal surface of embryo becomes the neural plate
development induced by chemical signals from mesoderm visible three weeks after conception neural plate cells= embryonic stem cells neural tube closes at anterior end first |
|
18 days of development
|
neural plate develops
tall, columnar cells develop, get thickened neural plate |
|
Day 21 of development
|
neural groove becomes present
|
|
Day 24 of development
|
neural tube fuses
|
|
Neural crest cells
|
come from neural plate; neural plate cells that escaped
become the neurons of the PNS |
|
anterior end of neural tube
|
becomes brain
cells proliferate much faster here than posterior end |
|
posterior end of neural tube
|
becomes spinal cord
|
|
spina bifida
|
some of the vertebrae overlying the spinal cord aren't fully formed; remain unfused and open
folic acid during pregnancy best way to prevent |
|
Neural tube
|
becomes the CNS
|
|
neural cavity
|
becomes the ventricles of the brain and central canal of spinal cord
|
|
Poliferation of Neurons and Glia
|
2nd stage of development
occurs in the ventricular zone, next to neural cavity |
|
Migration
|
Part of 3rd stage of development
Migrating cells are immature; lack axons and dendrites Two types of migration: radial migration tangential migration Methods of migration: somal glial-mediated migration |
|
radial migration
|
toward the outer wall of the tube
|
|
tangential migration
|
parallel to the tube wall
|
|
Somal migration
|
extension develops that leads migration, cell body flows
think snail |
|
Glial-mediated migration
|
cell moves along a radial glial network
|
|
radial glia
|
form guide wires; network
|
|
Aggregation
|
part of 3rd stage of development
Cells align themselves with other cells and form structures Gap junctions pass cytoplasm between cells |
|
Cell-adhesion molecules (CAMs)
|
aid in migration and aggregation
recognize and adhere to molecules on other cells |
|
Axon Growth
|
part of 4th stage of development
axons and dendrites differentiate extensions emerge from growth cones at tips of axons and dendrites |
|
filopodia
|
finger extensions coming from the growth cone
|
|
Lamelipodium
|
at the base of the growth cone
extensions that can help direct the developing axon in a specific direction |
|
Chemoaffinity hypothesis
|
For axon growth
target cells are releasing some sort of chemical that attract the developing growth cone to it target cells also release chemical repellents to keep other growth cones away uses chemoattractants and chemorepellents |
|
Bowe Print hypothesis
|
for axon growth
each neuron is built with internal blue print on where to go |
|
Topographic gradient hypothesis
|
for axon growth
keeping spatial relationships with neighbors two intersecting signal gradients (ephrins) |
|
Synapse formation
|
part of 4th stage of development
depends on presence of glial cells (astrocytes) high levels of cholesterol are needed chemical signal exchange between pre and postsynaptic neurons is needed |
|
synaptogenesis
|
6th stage of development
synapses form rapidly on dendrites and dendritic spines spines proliferate after birth, connections affected by experience |
|
Determinants of Neuron Survival
|
produce more neurons than we need
two conditions: must form synapse with target cell and receive a neurotrophin from that cell must be stimulated to release NT into synapse |
|
pruning
|
producing more neurons than we need
|
|
Neuron death and synapse rearrangement
|
5th stage of development
|
|
apoptosis
|
programmed cell death that occurs when synapses receive little neurotrophins
|
|
necrosis
|
passive cell death
|
|
synapse rearrangement
|
space left after apoptosis is filed by sprouting axon terminals of surviving neurons
leads to increased selectivity of transmission occurs caudal to rostral prefrontal cortex is last |
|
Myelination
|
final stage in development
occurs about 24 weeks postconception sensory regions myelinate before motor regions continues throughout life spinal cord, hindbrain, midbrain, forebrain |
|
Adult neurogenesis
|
declines with age
declines in dentate gyrus of hippocampus from old age |
|
Early life stress effects on developing brain
|
Amygdala
overexcitation alteration of GABA receptors Hippocampus decreased size decreased neurogenesis |
|
Phenylketonuria
|
hereditary disorder of protein metabolism
lacks enzyme to metabolize phenylalanine (amino acid in food) phenylalanine builds up and becomes toxic |
|
Down Syndrome
|
extra chromosome 21
impaired synaptogenesis degeneration of branching out of dendrites |
|
Fragile X syndrome
|
more common in males
Fragile X Gene= FMR1; prone to breaking FMRP protein dysfunction abnormal dendritic spines |
|
Autism Spectrum Disorder
|
Neurodevelopmental disorder
social impairment communication problems abnormal behavioral movements decreased area of corpus callosum fewer neurons in amygdala but increased activity when looking at faces more common in males brain develops more slowly overgrowth of gray matter |
|
Fusiform face area
|
gyrus in the temporal lobe
decrease in activity recognition of faces |
|
catgraphs syndrome
|
can't tell who anybody's face is
|
|
"Wiring up"
|
child brain development
synapse formation and rearrangement, myelination, wiring and rewiring, getting things ready |
|
Betz cell
|
motor cortex
#s decline around 50 years, many gone by 80 years large neuron in cortical layers 4 and 5 associated with descending motor information |
|
Inferior olive
|
unchanged
located on medulla associated with and located within the auditory system |
|
Shrinkage in brain aging
|
frontal cortex
hippocampus cerebellum striatum dementia and alzheimer's sulci widen corpus callosum area decreases |
|
Dementia with Lewy bodies
|
progressive cognitive decline
pronounced fluctuations in alertness and attention recurrent visual hallucinations parkinsonian motor symptoms |
|
Lewy Body
|
circular deposit of protein
alpha-synuclein protein |
|
Frontotemporal dementia
|
severely disrupts personality and social skills
damages anterior cingulate cortex, orbitofrontal cortex, temporal lobe, and frontal insula widened sulci often misdiagnosed as Alheimer's disease von Economo neurons are targeted |
|
Alzheimer's disease
|
Mild or Moderate
hippocampus shrinks initial cortical atrophy in parietal and temporal areas first then frontal lobe Autopsy shows: extensive neural degeneration tauopathy amyloid beta plaques acetylcholine levels low |
|
Mild AD
|
mild memory problems for new events and new info
increased difficulty thinking of words if noticed by other people, considered minor |
|
Moderate AD
|
other people will notice
anxiety, depression, paranoia spatial difficulty problems with math and organization difficulty understanding time, date, and place |
|
Pittsburgh Blue (PiB)
|
PET technique
imaging compound tries to determine accumulation of beta amyloid plaques |
|
Medications for AD
|
Cholinesterase inhibitors
NMDA receptor antagonist |
|
Choloinesterase inhibitors
|
medicine for AD
aricept, exelon keep acetylcholine levels high |
|
NMDA receptor antagonist
|
Namenda
regulates activity of glutamate by blocking areas in the brain that are overexcited by glutamate |
|
Brain tumors
|
Meningiomas
encapsulated infiltrating astrocytic tumors oligodendroglial tumors glioblastomas |
|
Meningiomas
|
encapsulated and tend to be benign
|
|
encapsulated
|
has boundaries
|
|
infiltrating
|
spreading throughout
|
|
astrocytic tumors
|
astrocytomas and anaplastic astrocytomas
|
|
glioblastomas
|
most aggressive type of primary brain tumor
|
|
Stroke
|
sudden onset, cerebrovascular event
|
|
cerebral ischemia
|
type of stroke
insufficient blood flow to the brain types: thrombosis embolism arteriosclerosis cerebral hypoxia damage is consequences of glutamateric excitotoxicity |
|
thrombosis
|
blood clot; typically forming in the brain
|
|
embolism
|
blood clot that forms somewhere else and gets dislodged and moves to the brain and lodges
|
|
cerebral hypoxia
|
death of brain tissue
|
|
cerebral hemorrhage
|
aneurysm
abnormal widening or ballooning of a portion of an artery due to weakness in the wall of the blood vessel |
|
coon
|
brain hits the front of the skull
|
|
contracoon
|
brain hits the back of the skull
|
|
Amyloid-beta peptide
|
normal product of cellular metabolism
essential for normal brain functioning regulates synaptic transmission in the hippocampus involved in cholesterol transport |
|
Encephalitis
|
infection of the CNS
inflammation of the brain parenchyma symptoms: headaches, flu-like symptoms, fever West Nile or Varicella-zoster virus |
|
Meningitis
|
Inflammation of the meninges
types: Viral infections (most common) bacterial meningitis parasitic menigitis fungal |
|
Bacterial meningitis
|
much less common
Streptococcus pneumonia: most common source of infection rapid onset can be fatal |
|
Parasitic meningitis
|
Naegleria fowleri enters the body through the nose
not common in US |
|
Fungal meningitis
|
Inhaling fungal spores
cryptococcus- inhaling soil contaminated with bird droppings histoplasma- environments heavy with bat feces |
|
Transverse myelitis
|
spinal cord inflammation
destroy/damage myelin which results in scars that interfere with motor neuron communication Results from: viral infection abnormal immune reactions complication of syphilis, measles, Lyme disease |
|
Brain abscess
|
accumulation of infectious materials within the CNS
|
|
Neurosyphilis
|
Teponema pallidum bacteria is cause
occurs in individuals with untreated syphilis for many years infects brain/spinal cord cognitive decline, seizures ocular disorders |
|
Creutzfeld-Jakob disease (CJD)
|
caused by a prion
lack of coordination, cognitive dysfunction, rapid progression, fatal Classic and Variant types may be related to Kuru |
|
prion
|
causes proteins to fold abnormally
|
|
Classic CJD
|
Sporadic or Familial
|
|
Sporadic CJD
|
happens but we don't know why
|
|
Familial CJD
|
hereditary form
|
|
Variant CJD
|
related to mad cow disease
caused by exposure to contaminated products |
|
Kuru
|
seen in New guinea women who ate brains of dead relatives as funeral ritual
|
|
Epilepsy
|
permanent changes in brain tissue cause the brain to be too excitable
causes: stroke, TBI, dementia, infections, brain tumor some medications symptoms: repeated, unpredictable seizures; staring spells; violent shaking (convulsions); subtle changes of thought, mood, or behavior |
|
Partial epilepsy
|
doesn't involve entire brain
types: simple complex |
|
simple partial epilepsy
|
symptoms are primarily sensory or motor or both
spread as epileptic discharge spreads spreads regionally |
|
complex partial epilepsy
|
restricted to temporal lobes
engages in automatisms: compulsive and repetitive simple behaviors |
|
Generalized epilepsy
|
involves entire brain
types: Grand mal Petit mal |
|
Grand mal epilepsy
|
loss of consciousness and equilibrium
Tonic-conic convulsions: rigidity (tonus) and tremors (clonus) resulting hypoxia |
|
Petit mal epilepsy
|
not associated with convulsions
disruption of consciousness associated with a cessation of ongoing behavior |
|
biological components involved in hunger
|
Hypothalamus
stomach blood sugar, insulin, hormones set point heredity |
|
Digestion
|
breaking down food and absorbing its constituents
|
|
Insulin
|
secreted from the pancreas
regulates the way the body uses glucose controls glucose production and release from liver levels high => glucagon levels low levels low => glucagon levels high |
|
Glucose
|
stored in the liver as glycogen
when glucose levels drop, liver converts glycogen to glucose glucose levels high => liver stops conversion of glycogen to glucose; converts glucose into glycogen for storage levels drop prior to a meal |
|
Glucagon
|
secreted by pancreas
converts glycogen to glucose |
|
Energy storage in the body
|
Energy is stored in fats, glycogen, and proteins
fats are most efficient |
|
Three phases of energy metabolism
|
Cephalic phase
Absorptive phase Fasting phase |
|
Cephalic phase
|
preparatory phase; preparation for eating
initiated by sight, smell, expectation of food insulin levels are high |
|
Absorptive phase
|
insulin levels are high
blood glucose is being utilized as form of energy excess glucose is converted into glycogen glycogen is stored in the liver |
|
Fasting phase
|
glucagon levels are high, insulin levels are low
energy that body needs is going to be drawn from the energy stores you made by eating converting fats into free fatty acids converting glycogen into glucose |
|
Dual-center theory
|
the hypothalamus contains two different regions
one acting to initiate eating and one to stop it |
|
Lateral hypothalamus (LH)
|
feeding center; hunger center
stimulation increases eating deactivated by glucose |
|
Ventromedial hypothalamic nucleus (VMH)
|
satiety center
stimulation decreases eating stimulated by glucose/ glucoreceptors |
|
Stomach
|
hunger pangs and feeling of fullness
contractions => hunger distension => satiety |
|
gut peptides
|
satiety signal
cholecystokinin (CCK) |
|
Letpin
|
secreted by fat cells
sensed by hypothalamus inhibits appetite |
|
Neuropeptide Y
|
manufactured in hypothalamus and gut; stimulates appetite
|
|
Set point
|
homeostatic brain mechanism defends some level of body weight
|
|
metabolic rate
|
rate at which body burns energy when at rest
|
|
Environmental factors of hunger
|
Food's pleasure
learning component taste preferences taste aversions |
|
Adaptive species-typical preferences
|
sweet and fatty foods = high energy
salty = sodium-rich |
|
Adaptive species-typical aversions
|
bitter= toxins
|
|
Orbital prefrontal cortex
|
If lesioned, causes you to eat less
input from olfactory system/bulb |
|
Types of Chemical Communication
|
autocrine funciton
paracrine function pheromone funciton allomone function endocrine funciton neurocrine function |
|
pheromone function
|
chemical indicators between individuals in the same species
|
|
allomone function
|
chemical communication between diff species
|
|
endocrine function
|
long distance communicator
goes into bloodstream, can go everywhere |
|
Features of the endocrine system
|
1. endocrine glands are ductless
2. have a rich blood supply 3. hormones secreted into bloodstream 4. hormones can travel to every cell in the body 5. hormone receptors interact with particular hormones |
|
Neurosecretory cells
|
receives info synaptically just like a neuron
release hormones instead of NT link between nervous system and circulatory system |
|
Hormones vs. NTs
|
hormones:
released into blood act at sites far from point of release graded responses slow NTs: release into synapse act locally all/none response fast |
|
Functions of hormones
|
modulate cell activity
promote growth, proliferation, and differentiation of cells modulate rate of function influence the probability of behavior |
|
Types of hormones
|
Protein/peptide hormones
amine hormones steroid hormones |
|
Protein/Peptide hormones
|
bind to receptors on outside of membrane
most rapid effects of all hormones ocytocin and ACTH |
|
Amine hormones
|
same relatively fast receptor response as protein hormones
|
|
Steroid hormones
|
bind to receptors within the cell
slow sexual actions and sexual development gonadal and adrenal hormones |
|
Hypothalamus
|
releases releasing hormones
paraventricular nucleus and subraoptic nucleus releases CRH releases TRH releases GnRH releases GnRI signals endocrine gland to secrete horomone, hormones effects target cells, target produces a response, this response feeds back to the hypothalamus to regulate continued secretion of hormone |
|
pituitary gland
|
hypophysis
one of the most regulated systems in endocrine system connected to hypothalamus two parts: anterior posterior |
|
anterior pituitary
|
adenohypophysis
derived during embryological development from the roof of the mouth connected to hypothalamus by hypohyseal protal system prolactin FSH and LH ACTH |
|
posterior pituitary
|
neurohypophysis
derived from nervous tissue two protein hormones released: oxytocin vasopressin synthesized in paraventricular and supraoptic nucleus has axons |
|
Testes
|
androgens
Leydig cells, T |
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ovaries
|
progestins, estrogens
|
|
placenta
|
Human chorionic gonadotropin, estrogen, progesterone
|
|
Ovulation
|
Corpus luteum secretes progesterone
egg not fertilized=> levels of progesterone decrease egg fertilized=> progesterone stays high |
|
Egg not fertilized
|
Progesterone and estrogen levels decrease
uterine lining sluffs off tells hypothalamus to secrete FSH and cycle happens all over again |
|
Egg is fertilized
|
progesterone levels stay high
uterine lining stays thick fertilizd egg secretes the human coreonic gonadotrpic hormone |
|
coreonic gonadotropic hormone
|
hormone looked for in pregnancy tests
|
|
Birth
|
Toward ends of pregnancy- placenta secretes large amounts CRH
then mom and fetus produce ACTH ACTH acts on adrenal cortex which secretes DHEA DHEA converted to estrogen by placenta, which results in increase levels of estrogen This causes smooth muscles of uterus to form gap junctions, contract together Oxtytocin is expressed Prostaglandins are synthesized- cause contractions |
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Organizational effects of hormones
|
early in development
"sensitive period" enable later behavior permanent determine male or female development |
|
activational effects of hormones
|
occur late in life, related to developmental period
transient effects occur when hormones enables certain types of behaviors to be more likely |
|
Chromosomal sex
|
determined at conception
XX-female XY- male |
|
Gonadal sex
|
determined later in development
Y chromosome controls development of glands that produce male sex hormones |
|
Before 6 weeks post fertilization
|
undifferentiated fetus
bipotential gonads Fetus has two sets of undeveloped internal reproductive ducts |
|
Wolffian duct system
|
undeveloped male system
|
|
Mullerian duct system
|
undeveloped female system
|
|
SRY Gene
|
on Y chromosome, produces tesits-determining factor
gonads develop into testes secrete testosterone, MIH |
|
XX
|
No SRY Gene
No TDF Ovary development Mullerian duct develops into fallopian tubes, uterus, and inner vagina No MIH |
|
Aromatization Hypothesis
|
androgens masculinize nervous system
|
|
Aromatase
|
enzyme that converts testosterone to estradiol
|
|
Alpha-fetoprotein
|
binds to estrogen and this complex can't cross the blood brain barrier
prevents estrogen from entering the brain so it doesn't masculinize |
|
SDN-POA
|
sexually dimorphic nucleus of pre-optic area
nuclei larger in males nucleus in hypothalamus involved in male copulatory behavior |
|
Testosterone in a male
|
right around birth, testosterone increase then decreases until puberty; large SDN-POA
|
|
Testosterone in a female
|
no rise in testosterone around birth or puberty; small SDN-POA
|
|
Brain and Hormone Activity in Male Mating
|
Input from estrous female, causes activity in olfactory bulbs and MPOA
causes surge in GnRH leads to rise in testosterone this facilitates sexual behavior copulation occurs |
|
Neurotransmitters involved in sexual behavior
|
Dopamine plays central role
|
|
Mesostriatal tract
|
controls muscular response for mounting
controls genital response |
|
Mesolimbocortical tract
|
controls sexual motivation
|
|
Medial Preoptic Area (MPOA)
|
body postures associated with sex
|
|
Oxytocin and Vasopressin
|
central players in regulation of species-specific social and reproductive behavior
|
|
Oxytocin
|
female sexual behavior, parturition, lactation, maternal attachment, pair bonding
|
|
Vasopressing
|
male erection and ejaculation, mediates aggression, territoriality, pair-bonding
|
|
ventral pallidum
|
contains vasopressin receptors
|
|
Androgen insensitivity
|
defect on the X chromosome of a male individual
mutation on the X chromosome of the AR gene (codes for androgen receptors) body does not masculinize no significant effect in females can't occur in chromosomal female |
|
Congenital Adrenal Hyperphasia (CAH)
|
genetic detect of the adrenal gland that can't produce vital hormones known as corticosteroids
|
|
phonemes
|
smallest unit in the sound system of language
|
|
morphemes
|
smalles grammatical unit of language
|
|
syntax
|
the way that different linguistic elements are combined together in phrases or in sentences
|
|
sensitive period
|
critical time to be exposed to languages for optimal learning
|
|
Broca's area
|
Brodmann areas 44 and 45
area 44= posterior inferior frontal gyrus; phonological verbal fluency processing, language production area 45= anterior inferior frontal gyrus; semantics |
|
arcuate fasiculus
|
connects Broca's area and Wernicke's area
|
|
Wernicke's area
|
Brodmann area 22
Three subarea |
|
1st subarea of Wernicke's area
|
responds to spoken words (self and others) and other sounds
|
|
2nd subarea of Wernicke's area
|
words spoken by someone else, when recalling a list of words
|
|
3rd subare of Wernicke's area
|
producing speech
|
|
planum temporale
|
located on superior temporal gyrus
superior portion of area 22 lies between primary auditory cortex |
|
angular gyrus
|
area 39
semantic processing |
|
supramarginal gyrus
|
area 40
phonological and articulatory processing of words |
|
When you hear a spoken word
|
processed first by primary auditory cortex
then Wernicke's area associates structure of word with representation of words stored in memory |
|
When you read a word aloud
|
processed first by visual cortex
then angular gyrus then Wernicke's area |
|
When you hear someone speak a word
|
Wernicke's area recognizes the word, then arcuate fasciculus, then Broca's area, then motor learning
|
|
Amnesia aphasia
|
comprehension of language is relatively intact
difficulty in finding names of objects Two kinds: one with noun one with verbs |
|
Wernicke's apashia
|
fluent aphasia
lack of comprehension "word salad" speech is fluent but doesn't make sense damage to left hemisphere in temporal parietal junction |
|
Auditory Agnosia
|
difficult recognizing spoken words
can't perform repetitive tasks or repeat instructions Two types: verbal: comprehension nonverbal: only environmental sounds |
|
surface dyslexia
|
difficult identifying words as a whole
errors in trying to pronounce complex or irregular words damage to left temporal lobe, fusiform gyrus, left inferior parietal lobe, angular and supramarginal gyro rely on pronunciation rules |
|
Advantages of lateralization
|
increased neural efficiency to concentrate function in one hemisphere
Two cognitive processes may be more readily performed simultanesouly |
|
propsopagnosia
|
can recognize objects not faces
acquired form brain trauma; fusiform gyrus |
|
Right hemisphere
|
perception of music
people that are profession key board players have larger corpus callosums relative to brain size |
|
Left hemisphere
|
planum temporale
perfect pitch |
|
Anatomic hemispherectomy
|
frontal, parietal, temporal, and occipital lobes removed
basal ganglia and thalamus left in place |
|
Functional hemispherectomy
|
smaller area of the affect hemisphere removed
|
|
split-brain individuals
|
corpus callosum severed
communication between left and right severed |
|
Motor Theory of evolution of hemispheric asymmetry
|
Left controls fine movements
left damage can produce motor and speech deficits |
|
Language theory of evolution of hemispheric asymmetry
|
primary role of left hemisphere is language
|
|
locked-in syndrome
|
high levels of awareness and arousal
completely paralyzed except being able to move eyelids result of massive brainstem lesion (stroke) |
|
coma
|
low arousal
low awareness |
|
vegetative state
|
high arousal
low/no awareness |
|
minimally conscious state
|
high arousal
low awareness that fluctuates |
|
persistent vegetative state
|
in vegetative state more than a month
|
|
permanent vegetative state
|
no awareness
high arousal 3 months for non-traumatic brain injury 1 year for traumatic brain injury |
|
awareness
|
thought to be dependent upon the functional integrity of the cerebral cortex and its subcortical connections
|
|
Bedside examination
|
look for eye tracking, motor and verbal responses
not recommended |
|
Glasgow coma scale
|
40% misdiagnosed
|
|
EEG and ERP
|
electroencephalogram and event-related potential
looking to see if there are action potentials responding to stimuli given |
|
Fronto-parietal network for consciousness
|
prefrontal cortex => parietal cortex => thalamus => prefrontal cortex
|
|
precuneus
|
"hub" in the network
where consciousness is located located in the posterior parietal cortex |
|
Thalamo-cortical
|
also important to consciousness
|
|
Circadian rhythm
|
24 hours
temperature, heart, respiration, metabolism in humans |
|
Ultradian rhythm
|
90 minutes
sleep |
|
infradian rhythm
|
more than 1 day
menstrual cycle |
|
circannial cycle
|
annually
hibernation |
|
phase shift
|
alter when you give cue for experiment
|
|
endogenous clock
|
superchiasmatic nucleus
|
|
entrainment
|
rhythm gets set to external cues
|
|
zeitgeber
|
external cue
|
|
superchiasmatic nucleus
|
recieves visual info directly from the eye
lies just above the optic chiasm projects to the paraventricular nucleus |
|
SCN clock cells
|
glucose metabolism increases during the day more than night
Each cell has own clock act in synchronized fashion |
|
Nature of clock cells
|
produce protein upon reaching critical level, inhibits own production
TIM and PER activate retinal ganglion cells |
|
retinohypothalamic pathway
|
consists of retinal ganglion cells that project to the SCN
|
|
paraventricular nucleus
|
connects with the pineal gland and secretes melatonin
|
|
Melatonin
|
secreted more the longer the night
suppresses reproductive gonadal output only applies to seasonal breeders |
|
Shift Work
|
phase advance/phase delay
can lessen by: rapidly rotating shifts better; one/two shifts max then diff time slow rotating shifts rotate shifts on weekly/monthly basis |
|
phase advance
|
rising early/going to bed early
|
|
phase delay
|
going to bed late/getting up late
|
|
Jet lag
|
East => West (better adjustment); day lengthened
West => East (1 day per 1 hour); day shortened |
|
NREM sleep
|
slow, high amplitude brain waves
initiated and maintained by forebrain |
|
REM sleep
|
fast, low amplitude waves, rapid eye movements
reduced muscle tone generated by brain stem |
|
Electroencephalograph (EEG)
|
used to study sleep
widespread cortical and subcortical systems generate the electrical rhythms of diff states/stages |
|
Waking Stage of Sleep
|
Alpha and Beta waves
beta activity associated with alertness |
|
Alpha waves
|
10-12 hertz
|
|
beta waves
|
13-40 hertz
|
|
Stage 1 of sleep
|
slow wave sleep
Vertex spike transition between wakefulness and sleep lasts about 10 minutes very easily awakened heart rate slows; muscle tension decrease theta waves |
|
theta waves
|
3.5-7.5 hertz
|
|
Stage 2 of seep
|
slow wave sleep
irregular brain waves bursts of activity sleep spindles about 15 minutes long if awakened would deny being asleep important for learning of motor tasks |
|
sleep spindles
|
bursts of activity
12-24 hertz last about 0.5 seconds |
|
Stage 3 of sleep
|
slow wave sleep
delta waves important for memory and learned facts |
|
delta waves
|
3.5 hertz
large amplitude |
|
Stage 4 sleep
|
Delta waves
hard to waken slow wave sleep important for memory and learned facts |
|
Slow wave sleep
|
important for memory
increase of glucose metabolism in frontal lobe more delta activity in frontal lobe when there is more brain power used during the day |
|
REM sleep
|
beta activity
lack of muscle tones vulnerable 80% report dreaming if awakened |
|
Polyphasic sleep cycles
|
infants and elderly
|
|
Naps
|
no REM or deep sleep
only get stage 1/2 |
|
Forebrain in sleep
|
produces a state of SWS
|
|
encephale isole
|
isolated brain
incision between medulla and spinal cord EEG alternates b/t periods of wakefulness and periods of sleep shows patterns of sleep are regulated by structures in the brain |
|
cerveau isole
|
isolated forebrain
incision in midbrain EEG rostral to incision shows constant SWS |
|
basal forebrain in sleep
|
generates SWS
when lesioned => no SWS releases GABA which suppresses activity in tuberomamillary nucleus in hypothalamus suppresses wakefulness |
|
Reticular formation in sleep
|
extends from medulla to forebrain
when stimulated, it activates the forebrain from sleep lesioned => persistent SWS |
|
Raphe nucleus in sleep
|
serotonin is synthesized here
serotonin release promotes SWS promotes SWS inhibits REM during SWS and wakefulness |
|
Pontine System in sleep
|
pons
Triggers REM sleep stimulating pons induces REM sleep pontogeniculociiptae waves (PGO waves) |
|
What happens during REM
|
acetylcholinergic neurons in pons are activated
Neurons project to: tectum lateral geniculate nucleus nuclei of medulla neurons in basal forebrain |
|
tectum in sleep
|
rapid eye movement
|
|
lateral geniculate nucleus in sleep
|
PGO waves
|
|
nuclei of medulla in sleep
|
muscular paralysis, GABA, glycine
|
|
neurons in basal forebrain area in sleep
|
cortical activation
|
|
Hypothalamic center in sleep
|
secretes protein Hypocretin
controls transitions between stages Neurons project to: basal forebrain reticular formation nuclei of medulla tuberommaillary nucleus |
|
Narcolepsy
|
loss of hypocretin
symptoms: extreme drowsiness every 3-4 hours dream-like hallucinations sleep paralysis cataplexy (loss of muscle tone) intrusion of REM into wakefulness |
|
hypocretin
|
protein secreted by the hypothalamic center that prevents transition from wakefulness directly into REM sleep
|
|
sleep attacks in narcolepsy
|
last about 15 minutes
typically occur after eating wake up and feel refreshed can happen at anytime |
|
Catplexy
|
sudden loss of muscle tone while awake
inability to move strong emotions can bring this on usually less than 30 seconds long |
|
Treatments for narcolepsy
|
lifestyle adjustments
medications: stimulants antidepressants |
|
antidepressants and narcolepsy
|
used to reduce episodes of cataplexy, sleep paralysis, and hallucinations
|
|
stimulants and narcolepsy
|
provigil
preferred because it is less likely to be abused |
|
Insomnia
|
trouble falling asleep/staying asleep
causes: poor sleep, lifestyle habits, medications, alcohol, caffiene |
|
Medications for Insomnia
|
Ambien
Intermezzo Melatonin |
|
Ambien (Zolpidem)
|
used for Insomnia
trouble falling asleep GABA-BZ receptor complex preserves deep sleep |
|
Intermezzo
|
for middle of the night wakefulness in Insomniacs
same as ambien just less |
|
Melatonin
|
mild effect for reducing time to fall asleep in insomniacs
|
|
Sleep apnea
|
one/more pauses in breathing or shallow breaths while you sleep, lasting a few seconds/minutes
|
|
Obstructive sleep apnea
|
blockage of narrow airway during sleep
surgery can be performed to remove excess tissue more common in overweight most common form of sleep apnea |
|
Central sleep apnea
|
less common
brain regions responsible for controlling breathing isn't working properly more common in some types of medical conditions |
|
Periodic movement limb disorder/ Restless leg syndrome
|
altered dopaminergic mechanisms
Parkinson's |
|
REM behavior disorder
|
act out dreams
physically move limbs result of damage to brainstem regions that are involved in inhibiting cranial and spinal nerves not sleepwalking |
|
sleepwalking and night terrors
|
occur in stages 3 or 4.
|
|
Agonistic Drug Effects
|
1. increase synthesis of NT
2. increase # of NT by destroying degrading enzymes 3. increase release of NT from terminal buttons 4. binds to autoreceptors and blocks their inhibitory effect on NT release 5. binds to postsynaptic receptors and activates or increases effect of NT 6. blocks deactivation of NT by blocking degradation/ reuptake |
|
Antagonistic Drug Effects
|
1. block synthesis of NT
2. causes NT to leak from vesicles then destroyed by enzyme 3. blocks release of NT from terminal buttons 4. activates autoreceptors and inhibits NT release 5. receptor blocker |
|
Oral injection of drugs
|
dissolved in stomach, carried to intestines, absorbed in bloodstream
|
|
advantages of oral injection of drugs
|
easy to administer
|
|
disadvantages of oral injection of drugs
|
influenced by amount and type of food in stomach, some metabolized in stomach, or can't pass membrane
|
|
Injection of drugs
|
subcutaneously
intramuscularly intravenously advantage: exact dosage known disadvantage: too much/allergy- not much can be done |
|
Inhalation of drugs
|
absorbed in bloodstream via capillaries in lungs
disadvantage: hard to regulate dosage, lungs may be damaged |
|
Therapuetic index
|
ratio b/t dose that produces desired effect in 50% of animals and dose that produces toxic effect in 50% of animals
|
|
Factors determining effet of drug
|
age
weight setting in which drug is used tolerance time of day |
|
drug tolerance
|
decreased sensitivity due to repeated exposure
|
|
cross-tolerance
|
one drug can produce tolerance to similar drugs
|
|
Functional drug tolerance
|
decreased responsiveness at site of action
decrease receptors decrease efficiency of binding at receptors receptors less responsive |
|
Conditioned drug tolerance
|
tolerance effects maximized when drug is taken in same environment as previously taken
|
|
Physical dependance theory
|
Biopsychological theory of addiction
not right because: addicts relapse after detox begin drug use not explained addictions develop to drugs without severe withdrawal symptoms |
|
Incentive-sensitization theory
|
Biopsychological theory of depression
anticipated pleasure associated with taking drug Hedonic value- actual value as the positive incentive value increases, the hedonic value decreases crave more; enjoy less |
|
Tobacco
|
Nicotine is main ingredient
changes number of receptors in nicotinic cholinergic receptors in CNS stimulates release of DA from NA decrease in monoamine oxidase |
|
Curare
|
targets acetylcholine
blocks nicotinic receptors at neuromuscular joint muscle relaxer |
|
Atropine
|
muscarinic receptors
decrease in parasympathetic activity of muscles, glands decrease glandular secretions, breathing difficulty, blocks vagus nerve |
|
Alcohol
|
blocks NMDA receptors
AMPA receptors (ligand gated) NMDA receptors (ligand and voltage) decreases GABA levels acts as an anxiolytic increases DA release in NA |
|
Wernicke-Korsakoff Syndrome
|
associated with alcohol
Wernicke: degenerative brain disorder caused by lack of vitamin B1 (thiamine) dietary deficiencies can result in this Korsakoff: memory disorder amnesia, disoriented, attention deficits confabulation (making up something) difficulty in retreiving memories difficulty acquiring new info Wernicke is initial stage then Korsakoff is chronic part |
|
Marijuana
|
THC is main active ingredient
acts on CB1 receptor in NS acts on substantial nigra, hippocampus, cerebellar cortex, cerebral cortex stimulates release of DA from NA contains endocannabinoids |
|
endocannabinoids
|
function as retrograde messengers
Anandamine alterations of memory formation, appetite stiumlation, reduced pain sensitivity |
|
Cocaine
|
stimulant
binds to DA re-uptake transporters on presynaptic membranes of DA neurons inhibits removal of DA from synaptic cleft and degradation by monoamine oxidase blocks reuptake transports for serotonin ventral tegmental area, NA, and caudate nucleus increases alertness, feelings of well-being, energy, and motor activity Tachycardia, hallucinations and elevated blood pressure => excessive prolonged use |
|
Ecstasy (MDMA)
|
binds to serotonin reuptake transporter
enters the serotonergic neuron via transporter, causing excessive release of serotonin similar effects on norepinephrine causes of release of DA |
|
opiates
|
heroin, morphine, codeine
effective analgesics act on delta, kappa, and mu opioid receptors all are metabotropic heroin is converted to morphine in the brain agonists at the receptors |
|
club drugs
|
GHB, Rohypnol, Ketamine, MDMA
|
|
GHB
|
CNS depressant
treat narcolepsy metabolite of GABE exists naturally in brain at low levels Acts on GABA receptor |
|
Rohphenol
|
date rape drug
Benzodiazepine Acts at GABA receptor sedation, muscle relaxation, reduction of anxiety not approved in US |
|
Ketamine
|
special K
dissociative anesthetic distorts perception of sight and sound used in Vets NMDA receptor target related to PCP |