NEUR 310 Lecture Notes - Lecture 18: Neuromuscular Junction, Synaptotagmin 1, Hair Cell
11 Apr 2017
School
Department
Course
Professor
Document Summary
Transmitter release - synaptic vesicles: classical transmitter release from the presynaptic side is fast transmission - all about optimization for speed. Two observations that neurotransmitters were released from vesicles: release is quantal - a single event, not graded. Invention of electron microscopy - able to see vesicles: when minimal stimulations are used, transmitter release is quantal: one quantum is one vesicle. Synaptic vesicles are clustered opposite neurotransmitter receptors: release is triggered by calcium; occurs very fast, calcium sensor must be intimately tied to fusion. Sizes of ejps (epsps) stimulated seemed to be unitized - there were size readings of "1" and "2" but never "1. 5: occasional spontaneous release, not stimulated by calcium, exactly the size of the unitary peak. Epsps are determined by the number of receptors, which may differ in each synapse - thus impossible to get anything like a quantal distribution.
