Developmental Changes in the Voltage-Gated Ca2+Channels (VGCC)That Mediate Acetylcholine (ACh) Release at the Transient Efferent-Inner Hair Cell Synapse

KEARNEY, GI; ZORRILLA DE SAN MARTÍN, J.; WEDEMEYER , C; ELGOYHEN, A.B; KATZ, E.

San Diego, Califonia

Congreso; 37th ANNUAL MIDWINTER MEETING ARO; 2014

Association for Research in Otoringolaryngology (ARO)

Since birth until the onset of hearing (postnatal day (P)12 in mice), inner hair cells (IHCs) are innervated by medial olivocochlear (MOC) efferent fibers. At P9-11, ACh release is supported by both P/Q and N-type VGCCs and negatively regulated by L-type VGCC, coupled to BK potassium channel activation. We previously reported that at P5-7, P/Q- but not N-type VGCC partially support ACh release and that block-ing BK channel increases the quantum content of evoked re-lease (m) (Zorrilla de San Martín et al., ARO Abstracts 2012). Our goal is now to determine which other type/s of VGCCs mediate ACh release at this (P5-7) and earlier stages (P3) and whether BK channels and L-type VGCCs are functionally coupled.