Open AccessDifferential expression of ryanodine receptor in the developing rat cochlea
Author(s) -
Y. Liang,
L. Huang,
J. Yang
Publication year - 2009
Publication title -
european journal of histochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.754
H-Index - 42
eISSN - 2038-8306
pISSN - 1121-760X
DOI - 10.4081/ejh.2009.249
Subject(s) - ryanodine receptor , calcium , extracellular , thapsigargin , cochlea , calcium in biology , efferent , intracellular , chemistry , medicine , endocrinology , microbiology and biotechnology , calcium signaling , hair cell , receptor , inner ear , biology , anatomy , biochemistry , afferent
Ryanodine receptors (RyRs) are one of the intracellular calcium channels involved in regulation of intracellular free calcium concentration ([Ca2+]i). The immunolocalization of RyRs was investigated in the developing rat cochlea at different postnatal days (PND). The change of [Ca2+]i in isolated outer hair cells (OHCs) was determined. Morphological results showed low expression of RyRs in the Kolliker’s organ from the PND 5 group. RyR expression in inner hair cells (IHCs) increased as the rats aged, and was mature after PND 14. RyRs in OHCs were expressed near the synaptic area of afferent and efferent nerves. RyRs in supporting cells were expressed widely and strongly. The application of ACh, ryanodine + ACh, and thapsigargin + ACh could induce a significant increase in [Ca2+]i in OHCs in the presence of extracellular calcium. This increase of [Ca2+]i induced by ACh was caused by not only the calcium influx through surface calcium channels, but also the calciuminduced calcium release (CICR) from intracellular RyR-sensitive calcium stores. Morphological and Ca imaging results suggested that RyRs expression is related to cochlear maturity, and may play an important role in its function