The Presynaptic Function of Mouse Cochlear Inner Hair Cells during Development of Hearing

• DOI: 10.1523/jneurosci.21-13-04593.2001
• Publication Date: 2018-04-05T14:20:19Z
• Authors: Dirk Beutner; Tobias Moser
• Keywords: Synaptogenesis; Ribbon synapse

Before mice start to hear at approximately postnatal day 10, their cochlear inner hair cells (IHCs) spontaneously generate Ca(2+) action potentials. Therefore, immature IHCs could stimulate the auditory pathway, provided that they were already competent for transmitter release. Here, we combined patch-clamp capacitance measurements and fluorimetric [Ca(2+)](i) recordings study presynaptic function of during maturation. Ca(2+)-dependent exocytosis subsequent endocytic membrane retrieval observed near date birth. potentials triggered in IHCs, which probably activates pathway before it becomes responsive sound. underwent profound changes Ca(2+)-channel expression secretion development. increased toward end first week, providing large secretory responses this period thereafter declined reach mature levels. The efficacy whereby influx triggers maturation, such vesicle fusion caused by a given current occurred faster IHCs. synaptic reflected ongoing synaptogenesis had been described previously morphological studies.