TY - JOUR
T1 - Chick hair cells do not exhibit voltage-dependent somatic motility
AU - He, David Z.Z.
AU - Beisel, Kirk W.
AU - Chen, Lin
AU - Ding, Da Lian
AU - Jia, Shuping
AU - Fritzsch, Bernd
AU - Salvi, Richard
PY - 2003/1/15
Y1 - 2003/1/15
N2 - It is generally believed that mechanical amplification by cochlear hair cells is necessary to enhance the sensitivity and frequency selectivity of hearing. In the mammalian ear, the basis of cochlear amplification is believed to be the voltage-dependent electromotility of outer hair cells (OHCs). The avian basilar papilla contains tall and short hair cells, with the former being comparable to inner hair cells, and the latter comparable to OHCs, based on their innervation patterns. In this study, we sought evidence for somatic electromotility by direct measurements of voltage-dependent length changes in both tall and short hair cells at nanometre resolution. Microchamber and whole-cell voltage-clamp techniques were used. Motility was measured with a photodiode-based measurement system. Non-linear capacitance, an electrical signature of somatic motility, was also measured to complement motility measurement. Significantly, chick hair cells did not exhibit somatic motility nor express non-linear capacitance. The lack of somatic motility suggests that in avian hair cells the active process resides elsewhere, most likely in the hair cell stereocilia.
AB - It is generally believed that mechanical amplification by cochlear hair cells is necessary to enhance the sensitivity and frequency selectivity of hearing. In the mammalian ear, the basis of cochlear amplification is believed to be the voltage-dependent electromotility of outer hair cells (OHCs). The avian basilar papilla contains tall and short hair cells, with the former being comparable to inner hair cells, and the latter comparable to OHCs, based on their innervation patterns. In this study, we sought evidence for somatic electromotility by direct measurements of voltage-dependent length changes in both tall and short hair cells at nanometre resolution. Microchamber and whole-cell voltage-clamp techniques were used. Motility was measured with a photodiode-based measurement system. Non-linear capacitance, an electrical signature of somatic motility, was also measured to complement motility measurement. Significantly, chick hair cells did not exhibit somatic motility nor express non-linear capacitance. The lack of somatic motility suggests that in avian hair cells the active process resides elsewhere, most likely in the hair cell stereocilia.
UR - http://www.scopus.com/inward/record.url?scp=12244255116&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=12244255116&partnerID=8YFLogxK
U2 - 10.1113/jphysiol.2002.026070
DO - 10.1113/jphysiol.2002.026070
M3 - Review article
C2 - 12527737
AN - SCOPUS:12244255116
VL - 546
SP - 511
EP - 520
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 2
ER -