An analysis of the presynaptic physiology at a vertebrate central synapse will be undertaken in this research. Synaptic potentials will be recorded with two intracellular microelectrodes, one presynaptic in the Mauthner axon and the other postsynaptic in a cranial relay neuron. The investigation is focused on a single synaptic contact. How transmembrane potential, ions, pharmacological agents and proteins associated with presynaptic vesicles act on the number of quanta available and the probability for release will be studied. The hypothesis to be examined is that quantal presynaptic events are produced by specific proteins interacting with Ca2+ to trigger neurosecretion. The experiments may elucidate the fundamental process(es) by which neurotransmitter is released from central nerve terminals and are important for understanding the mechanisms of cell communication.
