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101 Cards in this Set
- Front
- Back
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Mesolimbic Dopamine Pathway |
- Motivate behaviors required for survival and reproduction - More complex than simply producing pleasure - Animal must learn to predict danger or reward |
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Adaptive emotional circuit |
Makes our brains vulnerable to drug addiction |
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Chemicals found in nature… |
mimic or enhance the actions of dopamine in this pathway |
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Olds & Milner (1954 ) |
- Experiment involving electrical stimulation of the brain - Some animals behaved in a way that increased the amount of stimulation the - Lab animals will work to obtain electrical stimulation of certain brain areas y received - Rats will press lever up to 2000 times per hour for 24 hours - Rats will ignore food and water to continue working for electrical stimulation (Intracranial Self Stimulation (ICSS)) |
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Brain site giving rise to most powerful effects |
Medial Forebrain Bundle (MFB) |
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Addiction |
inability to control use of drug despite serious negative consequences - All drug addicts are habitual users but not all habitual users are addicts - Addicts continue to use a drug despite adverse effects on health and social life - Despite repeated efforts to stop. |
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Tolerance |
decreased sensitivity to the drug with continued use |
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Withdrawal |
the opposite effects of the drug itself - after significant drug exposure, suddenly stopping can produce withdrawal symptoms - symptoms are opposite effects of the drug itself - symptoms indicate the person is physically dependent on the drug - may be produced by the same neural mechanisms that caused tolerance - drug produces compensatory changes in the nervous system – produces tolerance - when drug is stopped the compensatory changes remain, producing withdrawal symptoms |
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Drug Craving |
strong to overwhelming desire for the drug |
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Relapse |
going back to the drug after being off it well past the withdrawal symptoms |
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Tobacco |
- psychoactive drug -> Nicotine - 4,000 other chemicals called tar - a leading cause of preventable death - 5 million premature deaths a year – 1 in 10 deaths - more deaths than “hard drugs” - smokers are drug addicts - strong craving for nicotine - withdrawal symptoms with quitting - depression, anxiety, irritability, constipation, insomnia - 70% of people who try cigarettes become addicted(compared to 10% for alcohol & 30% for heroin) |
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Alcohol: |
- 2 million deaths in the world each year - Major genetic component (heritability ~50%) - Low doses – can facilitate social interact - Moderate doses – degrees of cognitive, perceptual, verbal and motor impairment, socially unacceptable actions - High doses – loss of consciousness or death from respiratory depression - Mild withdrawal symptoms – hangover (headache, nausea, vomiting) |
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Full blown alcohol withdrawal |
- 5-6 hours: severe tremors, agitation, headache, nausea, vomiting, abdominal cramps, profuse sweating - 15-30 hours: convulsive activity - 3-4 days: Delerium tremens (DTs): halluconations, delusions, confusion, hyperthermia, tachycardia - can be lethal |
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endogenous opiates |
- released during behaviors important for survival and reproduction |
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Analgesic |
- during fighting must inhibit pain - periacuductal gray (PAG) responsible for these effects |
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Reinforcing |
- during mating must motivate animal to perform risky behavior - Exogenous opiates (e.g. heroin) - opiate receptors in VTA and NA involved in these effects |
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Opiate withdrawal symptoms: |
- 12 hours after last injection - sweating, yawning, tearing, restless sleep - 2-3 days - pupils dilate, violent yawning, crying, sneezing, nausea, vomiting, diarrhea, chills, sweating, insomnia, - Goosebumps - “cold turkey”, muscle spasms - “kick the habit” |
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Cocaine |
blocks the dopamine transporter - decreases re-uptake of dopamine |
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Amphetamines |
increases the release of dopamine from terminals |
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if a dopamine receptor antagonist is injected into NA... |
cocaine loses its reinforcing effects |
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cocaine tolerance |
- chronic use sensitizes dynorphin neurons - decrease release of dopamine |
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when Cocaine is stopped |
- Dynorphin still decreases dopamine release - produces dysphoria |
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Marijuana |
- THC is active ingredient (from resin on leaves) - typically smoked or ingested - Small doses: effects are subtle - High doses: Impairment of short-term memory, Difficulty with tasks involving multiple steps, Slurred speech, Sense of unreality, Sensory distortion, Paranoia, Motor impairment - increases dopamine release in NA |
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for most people speech is on the... |
left side of brain - in 95% of right-handed people - in 70% of left-handed people |
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Right side |
design, creativity - specialized in analysis of shapes and forms |
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Left side |
Logical, analytical - specialized in analysis of sequences of stimuli |
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Broca’s area |
speech production - located in the cortex of the dominant frontal lobe. - Damage in this area causes Broca's aphasia, characterized by hesitant and fragmented speech with little grammatical structure |
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Wernicke’s area |
speech comprehension - located in the cortex of the dominant temporal lobe. - Damage in this area causes Wernicke's aphasia, characterized by superficially fluent, grammatical speech but an inability to use or understand more than the most basic nouns and verbs. |
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CVA in Broca’s area |
disrupts ability to speak - called Broca’s Aphasia |
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Primary Symptom of Broca’s Aphasia |
- slow, labored and non-fluent speech - difficulty getting words out but words have meaning - Patients have something to say, they just can’t say it |
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Agrammatism |
difficulty using grammatical construction |
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Anomia |
word finding difficulty - omit words or use inappropriate words - say “ah” and “um” a lot |
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Speech comprehension |
- Involves Wernicke’s Area & Posterior Language Area - Neural circuits in the middle and posterior portion of the superior temporal gyrus of the left hemisphere (portion of auditory association cortex) |
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Wernicke’s aphasia |
Poor speech comprehension and production of meaningless speech = Pure Word Deafness + Transcortical Sensory Aphasia - Speak fluently - not searching for words - grammatical - use tonal inflection - just makes no sense - “word salad” |
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Damage to Arcuate fasiculus |
produces Conduction Aphasia - Can repeat words ONLY if the words have meaning can repeat “bicycle”, “hippopotamus”, but not “rilld” - Can repeat words with meaning because the connection between Posterior Language Area and Broca’s Area is intact because direct connection between Wernicke’s Area and Broca’s Area is damaged - cannot repeat words simply on recognition |
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Parkinson’s |
Neurological disorder of movement – 0.5% of population - 2.5 times more likely in men than women - Progressive Starts - slowly - Early- slight tremor of fingers |
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Full blown Parkinson’s |
- tremor during inactivity - muscular rigidity - difficulty initiating movement - slowness of movement - mask-like face - no intellectual impairment |
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parkinsons treatments |
L-DOPA - Effective treatment - symptoms greatly reduced – back to normal activities - Treats symptoms but doesn't prevent cell death in the substantia nigra - Need higher and higher doses (can produce psychotic like symptoms) - Eventually becomes ineffective |
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MPP+ neurotoxin produces |
Parkinson’s - disease does NOT run in families |
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parkinsons Neurosurgery |
- Lesion globus palidus - Electrical stimulation of thalamus |
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Autism |
- Reduced ability to interpret the emotions of others - 75% are male, 75% have mental retardation, 35% have epilepsy - Reduced capacity for social interaction and communication - Preoccupation with a single subject or activity - Idiosyncratic preoccupations - Repetitive behaviors, motor patterns - Sensory sensitivities - Resistance to change |
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autism Earliest signs: (appears before the age of 3) |
- failure to respond to own name - failure to look at parents face |
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Echolalia |
meaningless repetition of another person's spoken words as a symptom of psychiatric disorder. |
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Savant skills (1 in 10) |
- superior ability in specific skills seen at much greater than expected rates - Exceptional abilities in music, calculation, calendar calculation, feats of memory, drawing |
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Biological marker of autism |
- elevated blood levels of serotonin (25-30% of cases) - Serotonin reuptake inhibitors positive effect on some symptoms - Symptoms worse after tryptophan depletion |
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Brain structure in autism |
- brain is enlarged 3-10% (MRI and postmortem studies) - Most pronounced in early childhood (2-4 years) |
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austism: Amygdala/temproal lobe |
- Abnormalities in size, density and dendritic arborization of neurons in the limbic system (e.g., amygdala, hippocampus) - Suggests a curtailment of normal development - Damage to amygdala shortly after birth in monkeys produces social isolation, lack of eye contact, impaired facial expression and repetitive motor patterns |
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autism: Temporal lobe function |
- autism associated with deficits in face recognition skills - Region in temporal lobe -> fusion gyrus - Autistics may see faces as objects |
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Early prenatal origin of autism: evidence |
- Thalidomide given to pregnant women for morning sickness and also given in early weeks of pregnancy can increase probability that child would be autistic - Produced shortening of brainstem - Smaller than normal facial nucleus - Absence of superior olive nucleus(relay nucleus for auditory information) |
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neuroplasticity |
ability of brain to change |
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Learning and memory= |
different aspects of the same neuroplastic phenomenon |
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Learning = |
induction of experience-induced neural changes |
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Memory |
= maintenance of these neural changes and expression in the form of a behavioral change |
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Hippocampus |
(temporal lobe) - the center of emotion, memory, and the autonomic nervous system. - Structure critical to learning |
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Long term potention(LTP): |
- activation of synapses & NT release - depolarization of postsynaptic dendritic spine |
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Glutamate = |
major excitatory NT in brain |
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When postsynaptic cell is slightly depolarized... |
- Mg++ is ejected - Ca++ rushes in |
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Ca++ enters cell only when... |
glutamate is released AND postsynaptic membrane is depolarized |
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LTP only occurs in structures known to be... |
involved in learning and memory - e.g. hippocampus, cortex, thalamus, amygdala - (demonstrated in human cortex removed for neurosurgical reasons) |
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amnesia |
a partial or total loss of memory |
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Anterograde amnesia |
is a loss of the ability to create new memories after the event that caused the amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. |
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Retrograde Amnesia |
a loss of memory-access to events that occurred, or information that was learned, before an injury or the onset of a disease. |
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Explicit memories |
- requires conscious thought—such as recalling who came to dinner last night or naming animals that live in the rainforest. |
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implicit memories |
- acquired and used unconsciously, and can affect thoughts and behaviors. - uses past experiences to remember things without thinking about them. - its most common forms is procedural memory, which helps people performing certain tasks without conscious awareness of these previous experiences. |
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Prefrontal Cortex Damage |
Thought to house our most complex intellectual functions - Patients with damage show no memory deficits on conventional memory tasks - If tested carefully show two very specific memory deficits |
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Infant Amnesia |
is the inability of adults to retrieve episodic memories which are memories of specific events (times, places, associated emotions, and other contextual who, what, when, and where) before the age of 2–4 years as well as the period before age 10 of which adults retain fewer memories than might otherwise be expected given the passage of time |
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Major Depressive Disorder |
(clinical depression) - depths of despair - anhedonia - can’t keep a job - don’t maintain social contacts - fail to eat or maintain personal hygiene - sleep disturbances - thoughts of suicide - lasts for more than two weeks |
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anhedonia |
inability to feel pleasure |
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Bipolar Disorder |
(manic depression) - alternating periods of mania and depression - sense of euphoria that is not justified by reality - 30% attempt suicide |
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Mania |
mental illness marked by periods of great excitement, euphoria, delusions, and overactivity. - usually lasts for several weeks - follow by Depressive phase which usually 2-3 times longer |
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Unipolar Disorder |
(Major Depression) - long periods of depression - no mania - strong feelings of guilt or being bad or unworthy - very little energy - disturbed sleep - Anhedonia - strikes women 2-3 times more often than men - 15% attempt suicide |
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depression heritability |
- runs in families - people with close relative with depression are 10 times more likely to develop depression - Concordance rate:monozygotic = 69% (in same or different homes)dizygotic = 13% |
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Treatments for Depression |
- Monoamine oxidase (MAO) inhibitors - Tricyclic Antidepressants - Selective serotonin reuptake inhibitors (SSRIs) |
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Monoamine oxidase (MAO) inhibitors |
- Used to treat tuberculosis - noted that it elevated patients mood - MAOA - break down of two monamines (5-HT, NE) - MAO inhibitors increase levels of 5-HT, NE available for release |
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Tricyclic Antidepressants |
- Increase NE & 5-HT synaptic transmission by blocking transporters - SSRI’s = selective serotonin reuptake inhibitors |
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Selective serotonin reuptake inhibitors (SSRIs) |
- Increase 5-HT synaptic transmission by blocking transporters - believed to increase the extracellular level of the neurotransmitter serotonin by limiting its reabsorption into the presynaptic cell, increasing the level of serotonin in the synaptic cleft available to bind to the postsynaptic receptor. |
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Electroconvulsive Therapy |
- a procedure, done under general anesthesia, in which small electric currents are passed through the brain, intentionally triggering a brief seizure. - seems to cause changes in brain chemistry that can quickly reverse symptoms of certain mental illnesses. - Does not help psychotic symptoms - but dramatically improves depression - Prolonged ECT causes brain damage but probably saves many lives |
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Transcranial magnetic stimulation (TMS) |
- Apply strong localized magnetic field into brain electrical current through a coil of wire on scalp - No seizure, no memory loss or cognitive impairment - TMS applied to prefrontal cortex reduces symptoms of depression |
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Monoamine Hypothesis of Depression |
- depression is associated with under-activity at serotonergicand/or noradrenergic synapses - simply because increasing monoamine function reduces symptoms of depression - Monoamine antagonists can cause depression - depletes monoamines in synaptic terminal |
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serotonin |
- is a monoamine neurotransmitter. - is key player in depression - thought to be a contributor to feelings of well-being and happiness.[10] |
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Lithium |
- helps reduce the severity and frequency of mania. - may also help relieve or prevent bipolar depression. |
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problems with treating bipolar disorder with LITHIUM |
Therapeutic index is low - difference between an effective dose and an overdose Compliance is low - patients miss the “high” of the manic phase - pharmacological effects are unknown |
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Major symptom of depression is... |
sleep disturbances - True major depression: not sleeping all the time but increases in the number of wakings in the night and waking early in morning |
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Sleep and depression |
- All drugs that reduce REM sleep act as antidepressants (& vice versa) - Suggests that primary effect of SSRI’s may be to reduce REM sleep |
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Seasonal Affective Disorder (SAD) |
is a type of depression that's related to changes in seasons - Has strong genetic basisgene: encoding melanopsin, photopigment that detects light in retina synchronizes circadian rhythms - Incidence higher in northern US. (9% versus 1.5% in Florida) - Winter depression is associated with a polymorphism associated with serotonin transmission - Serotonin agonists alter clock gene levels |
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Schizophrenia |
a long-term mental disorder of a type involving a breakdown in the relation between thought, emotion, and behavior, leading to faulty perception, inappropriate actions and feelings, withdrawal from reality and personal relationships into fantasy and delusion, and a sense of mental fragmentation. - 1% of individuals of all races and cultural groups |
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Positive Symptoms of Schizophrenia |
- Delusions - Hallucinations - Thought disorder - Abnormal psychomotor activity |
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Delusions |
Having firm beliefs that are clearly not true; common delusion themes include: - thoughts of persecution (e.g. being followed or poisoned) - thoughts of grandeur (e.g., convinced of special powers or abilities) - thoughts of control (e.g., some external force is controlling thoughts, feelings) |
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Hallucinations |
Auditory hallucinations (hearing voices often berating or commanding) - e.g., “you are evil”, “you are the devil”, “kill yourself” - Olfactory hallucinations (smelling odors like poisonous gas) |
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Thought disorder |
- Having trouble organizing or connecting thoughts in a logical way - produces disorganized speech |
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Abnormal psychomotor activity |
- Agitated body movement, repeating motions over and over; - May become catatonic and completely stop all movement |
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Negative Symptoms of Schizophrenia |
- Social withdrawal - flat effect - Lack of initiation and motivation - Poverty of speech; alogia |
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Social withdrawal |
Reduced interaction with friends and family, isolation, a ‘loner’ |
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flat effect |
Failure to start or complete tasks, lack of goal directed behavior |
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Lack of initiation and motivation |
expressions of emotion are lacking or inappropriate |
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Poverty of speech; alogia |
Reduced or absent speech |
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Cognitive Symptoms of schizophrenia |
- Impaired attention: Trouble focusing on the task at hand - Impaired memory: trouble holding something in memory in the short term. Trouble remembering the who, what, when, where and why of past experiences - Impaired executive control: Problems changing behavior as demands in the environment change. Trouble with decision making - Impaired social-emotional processing:Reduced ability to read the intentions and emotions of others |
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Development of schizophrenia |
- Not clear what causes it - A biological disorder that may be triggered by environmental factors - runs in families - rises to 10% with a first degree relative with schizophrenia – even if adopted - elevated levels of interleukin-8 may be a cause |
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Chlorpromazine (Thorazine) |
– first antipsychotic medication for schizophrenia - Dramatically reduced positive symptoms - Led to development of additional medications like Haloperidol (Haldol) and Spiroperidol (Spiperone) |
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tardive dyskinesia |
Repetitive involuntary movements such as grimacing, tongue protrusion, eye blinking, shuffling gait |
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Dopaminergic hyperactivity in nucleus, accumbens, and amygdalaproduces |
- positive symptoms alleviated with dopamine receptor antagonists |
