PHGY 209 Lecture Notes - Lecture 5: Ligand-Gated Ion Channel, Inhibitory Postsynaptic Potential, Membrane Potential
12 Jan 2018
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Document Summary
A single neuron, through its branching axon may make synapses with many other neurons. As the action potential approaches the end of the axon, the structure of the axon changes to a bigger structure at the presynaptic terminal. Note that the presynaptic terminal of the axon and the postsynaptic spine (dendrite of another neuron) don"t touch. Synaptic cleft: space between the presynaptic terminal of the axon and the postsynaptic spine. Synaptic cleft important as presynaptic terminal releases a neurotransmitter chemical that diffuses across the synaptic cleft fast. Remember diffusion is effective over short distances. Presynaptic vesicles outer membrane made of the same components as the membrane of the axon (myelin sheath), it"s a lipid bilayer too that forms the sphere. Filled with thousands of neurotransmitters molecules that will be released in the synaptic cleft when signaled to. They release neurotransmitter when synapse is activated.
