NPB 100 Lecture Notes - Lecture 6: Voltage-Dependent Calcium Channel, Chemical Synapse, Stellate Ganglion
13 Feb 2018
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Neurotransmitter release: neurons often communicate with each other at chemical synapses. Nt release does not require na: add ttx to block presynaptic action potentials. Then apply current pulse to depolarize presynaptic terminal. Record amplitude of the p. s. p. as indirect measure of amount of. Nt release: results: ttx blocks voltage-gated na+ channels, but depolarizing presynaptic terminal still elicits postsynaptic response. Therefore v-gated na+ channels not needed: postsynaptic response not recorded until presynaptic depolarization was > 45mv. After that, postsynaptic response increases rapidly as function of presynaptic depolarization.
