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Postsynaptic Recordings at Afferent Dendrites Contacting Cochlear Inner Hair Cells: Monitoring Multivesicular Release at a Ribbon Synapse
Published on: February 10, 2011
Elementary properties of Ca(2+) channels and their influence on multivesicular release and phase-locking at auditory
Jacopo Magistretti1, Paolo Spaiardi2, Stuart L Johnson3
1Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia Pavia, Italy.
Abstract:
Voltage-gated calcium (Cav1.3) channels in mammalian inner hair cells (IHCs) open in response to sound and the resulting Ca(2+) entry triggers the release of the neurotransmitter glutamate onto afferent terminals. At low to mid sound frequencies cell depolarization follows the sound sinusoid and pulses of transmitter release from the hair cell generate excitatory postsynaptic currents (EPSCs) in the afferent fiber that translate into a phase-locked pattern of action potential activity. The present article summarizes our current understanding on the elementary properties of single IHC Ca(2+) channels, and how these could have functional implications for certain, poorly understood, features of synaptic transmission at auditory hair cell ribbon synapses.
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