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Preliminary Characterization of Voltage-Activated Whole-Cell Currents in Developing Human Vestibular Hair Cells and Calyx Afferent Terminals
- Source :
- JARO: Journal of the Association for Research in Otolaryngology
- Publication Year :
- 2014
- Publisher :
- Springer Science and Business Media LLC, 2014.
-
Abstract
- We present preliminary functional data from human vestibular hair cells and primary afferent calyx terminals during fetal development. Whole-cell recordings were obtained from hair cells or calyx terminals in semi-intact cristae prepared from human fetuses aged between 11 and 18 weeks gestation (WG). During early fetal development (11–14 WG), hair cells expressed whole-cell conductances that were qualitatively similar but quantitatively smaller than those observed previously in mature rodent type II hair cells. As development progressed (15–18 WG), peak outward conductances increased in putative type II hair cells but did not reach amplitudes observed in adult human hair cells. Type I hair cells express a specific low-voltage activating conductance, G K,L. A similar current was first observed at 15 WG but remained relatively small, even at 18 WG. The presence of a “collapsing” tail current indicates a maturing type I hair cell phenotype and suggests the presence of a surrounding calyx afferent terminal. We were also able to record from calyx afferent terminals in 15–18 WG cristae. In voltage clamp, these terminals exhibited fast inactivating inward as well as slower outward conductances, and in current clamp, discharged a single action potential during depolarizing steps. Together, these data suggest the major functional characteristics of type I and type II hair cells and calyx terminals are present by 18 WG. Our study also describes a new preparation for the functional investigation of key events that occur during maturation of human vestibular organs.
- Subjects :
- hair cells
Voltage clamp
Biology
Membrane Potentials
Calyx
Fetal Development
Hair Cells, Vestibular
03 medical and health sciences
0302 clinical medicine
Current clamp
Humans
human
development
Vestibular Hair Cell
030304 developmental biology
Vestibular system
Afferent Pathways
0303 health sciences
vestibular
Depolarization
electrophysiology
Sensory Systems
Cell biology
Electrophysiology
Otorhinolaryngology
Neuroscience
030217 neurology & neurosurgery
Research Article
Type II Hair Cell
Subjects
Details
- ISSN :
- 14387573 and 15253961
- Volume :
- 15
- Database :
- OpenAIRE
- Journal :
- Journal of the Association for Research in Otolaryngology
- Accession number :
- edsair.doi.dedup.....05d5891fc6d023de815f60ac5541df89