Modeling the hair-cell to spiral ganglion synapse: Berkeley Ear Club

Colloquium | February 27 | 4 p.m. | 3105 Tolman Hall

 Eric Young, John Hopkins University

 Department of Psychology

The synapse between hair cells and auditory nerve fibers provides precise temporal information about acoustic events, such as transients in complex stimuli and the phase of sound waveforms at frequencies up to the kHz range. To accomplish these tasks, the synapse produces a high rate of spontaneous and stimulus-driven discharge in auditory-nerve fibers, with irregular spike trains and little or no temporal summation of presynaptic events. In this talk, recent recordings from the auditory-nerve terminals on hair cells are described. The extent of temporal summation of separate presynaptic vesicle release is shown to be minimal in producing excitatory postsynaptic currents. Several properties of auditory nerve spike trains, including irregularity and the excess-variance observed in spike counting statistics are shown to be properties of the presynaptic release process.