L06-Neurotransmitters

L06-Neurotransmitters - 2/6/07 Neurotransmitters and...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
2/6/07 Neurotransmitters and Receptors Postsynaptic Potentials o EPSP Excitatory Increases probability that neuron will fire an action potential Sodium ion Axon hillock (spike initiating zone; voltage-gated sodium channels found here) reaches threshold; action potential is triggered in postsynaptic axon o IPSP Inhibitory Decreases probability that neuron will fire an action potential Efflux of Potassium ions or influx of Chloride ions Counteract EPSPs; action potential is not triggered Two kinds of integration o Temporal summation A single input fires rapidly, raising the postsynaptic potential above threshold o Spatial summation Many inputs fire simultaneously (or nearly so) Neurotransmitter Inactivation o Two mechanisms: ways to inactivate the neurotransmitter Reuptake: neurotransmitter binds to postsynaptic cell; taken back up into presynaptic; recycled and reused; presynaptic neuron or glia cells clear the space; active transport used bring back up into the presynaptic cell Enzymatic Degradation: chemical in cleft that breaks down neurotransmitter; effect of neurotransmitter wears off; enzymes made by
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 3

L06-Neurotransmitters - 2/6/07 Neurotransmitters and...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online