Term
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Definition
| –Divergence is when a single neuron communicated with several other neurons |
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Term
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Definition
| –Convergence is when a single neuron receives communication from several other neurons. |
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Term
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Definition
–The summing of postsynaptic potentials
Adding effects of graded potentials |
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Term
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Definition
–Are graded potentials
–Can be summed |
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Term
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Definition
–Are graded potentials
–Can be summed |
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Term
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Definition
Types of summation:
–Temporal: one synapse through time |
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Term
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Definition
Types of summation:
–Spatial: several synapses at the same time |
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Term
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Definition
•Axon C release neurotransmitter which causes an EPSP of 10 mV in neuron X.
•Does not reach threshold
•E has no direct impact on the membrane potential of X.
•When Axon E and C are active, the release of neurotransmitter from C causes a 15 mV EPSP which is sufficient to reach threshold.
•This works, because when E releases neurotransmitter, it causes a depolarization in the Vm of C.
•Thus when an action potential reached the nerve terminal of neuron C it sums with the existing depolarization.
•This greater depolarization means greater neurotransmitter release. |
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Term
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Definition
•Normally, when F and G are both active they can cause EPSPs in neuron Y that can sum to reach threshold.
•When H is active, it causes decreases the neurotransmitter release from F keeping the EPSPs caused by F and B both being active below threshold.
•H has no direct impact on the Vm of neuron X.
•This works because, when neuron H releases neurotransmitter it causes a hyperpolarization in neuron F.
•When an action potential arrives at the terminal of neuron F it sums with the hyperpolarization.
•This can dramatically reduce or eliminate neurotransmitter release from F.
•Thus F and G no longer can cause EPSP large enough to reach threshold. |
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Term
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Definition
•Found in PNS and CNS
•Most abundant neurotransmitter in PNS
•Synthesis
–Acetyl CoA + choline acetylcholine + CoA
–Synthesized in axon terminal
–Choline acetyl transferase (CAT) = enzyme for synthesis
•Breakdown
–Acetylcholine acetate + choline
–Occurs in synaptic cleft
–Acetylcholinesterase (AChE) = enzyme of degradation |
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Term
| Choline Acetyltransferase |
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Definition
| (CAT)enzyme for synthesis |
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Term
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Definition
| (AChE) enzyme of degradation |
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Term
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Definition
derived from tyrosine
•Dopamine
•Norepinephrine (noradrenalin)
•Epinephrine (adrenalin) |
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Term
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Definition
| (MAO)Enzymes for degrading biogenic amines |
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Term
| Catechol-O-methyltransferase |
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Definition
| (COMT)Enzymes for degrading biogenic amines |
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