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44 Cards in this Set
- Front
- Back
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Central gray matter (spinal cord)
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neuronal cell bodies, dendrites, synapses
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Dorsal horn
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sensory region of gray matter
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Ventral horn
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motor region of gray matter
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White matter (spinal cord)
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ascending sensory information, descending motor information
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Ventral root
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motor neuron axons
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Dorsal root ganglia
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sensory neuron cell bodies
one axon into spinal cord, other into periphery |
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Forebrain (prosencephalon)
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cerebral cortex
basal ganglia thalamus hypothalamus |
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Midbrain (mesencephalon)
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superior/inferior colliculi
midbrain tegmentum |
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Hindbrain (rhombencephalon)
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medulla oblongata
cerebellum pons |
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basal ganglia
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motor control, cognitive process
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thalamus
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gateway to cerebral cortex
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superior colliculus
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eye movement
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inferior colliculus
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auditory sensation
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midbrain tegmentum
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motor control, pain
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medulla oblongata
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visceral regulation
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interneurons
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inhibitory input to opposing muscle groups through short axons to nearby neurons in spinal cord.
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conductance
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'leakage'
limits the distance of nervous signal |
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capacitance
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'smearing'
frequency-dependent (high frequency = easy attenuation) limits speed of nervous signal |
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glial cells
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scaffolding
provide myelin sheath (decrease conductance/capacitance) saltatory conduction |
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Nodes of Ranvier
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breaks in ensheathment w/ concentrated Na channels
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multiple sclerosis
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myelination disease causing action potential increase in capacitance and/or conduction
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Total energy equation
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E = qV + RTln(C)
=electrical + chemical |
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thermodynamic equilibrium
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no NET movement of ions
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Nernst potential
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Vm = Vi-Vo = 58mV/z*ln(Co/Ci)
-z = ion's charge -Vm = membrane voltage |
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transporter
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couples movement of two or more ions/molecules
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Nernst potential list
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K (-90)
Cl (-70) Na (+55) Ca (+110) |
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reversal potential
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Vm for which there is no net electrical current passing through a channel
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inward rectifier K channels
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the principle channels open at rest in a neuron
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Multi-ion pore mechanism
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single ion binding is tight
-second ion energy canceled by repulsion (ion moves out easily) -different ion will not have cancellation effect (wont enter) -energetically NEUTRAL transport of specific ions |
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connexins
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six connexin molecules make up hemichannel (connexon)
-conducts electrical signaling -can conduct depol or hyperpol -synchronizes connected Vm's |
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Calcium hypothesis
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AP depolarization elicits volt-gate calcium influx-->neurotransmission
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Quantal hypothesis
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NT released in quanta
lowering extracellular [Ca] and increasing extracellular [Mg] lowers quanta #, not quanta size |
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mini end-plate potentials (Mepp)
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spontaneous release of single quanta at synapses.
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Vesicle hypothesis
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small clear vesicles contain ACh and AA's.
-close to active zone Dense core vesicles contain neuropeptides -not near active zone NT released by fusion, recycled by endocytosis |
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SNARE
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necessary for vesicle fusion in vesicle hypothesis
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synaptotagmin
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contains calcium binding sites
-detects presynaptic increase in [Ca] |
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Small-molecule NT's
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Acetylcholine
Amino acids (glutamate, aspartate, glycine, GABA) Monoamines (dopamine, NE, E, serotonin) -contained in active zone vesicles |
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Neuropeptides
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large precursors, translocated in ER, packaged in Golgi
-diffusible to distant postsynaptic sites -contained in dense core vesicles |
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ligand-gated ion channels
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ACh-R, glutamate receptors
-multimeric -rapid, phasic regulation of Vm |
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G protein-coupled receptors
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A: adrenergic, serotonergic, dopaminergic (rhodopsin)
B: peptide-binding, large extracellular domain C: large extracellular and intracellular domains -desensitized by C' phosphorylation |
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Scaffold examples
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PDZ domain proteins
arrestins non-PDZ scaffolds |
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desensitization
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phosphorylation (PKA, PKC, GPCR kinase GRK)
-dissociated G protein recruits GRK -Arrestins bind phosphorylated GPCR and block activation -Arrestin recruits clathrin for internalization |
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RGS proteins
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regulators of G-protein signaling
-GTPase-activating (faster inactivation) |
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presynaptic uptake of NT (termination)
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Na/Cl dependent: GABA, NE, dopamine, serotonine, glycine, choline
-AA transporters coupled w/ Na influx, K efflux -vesicular transporters -transporters may reverse based on gradient. |
