Cysteine-string protein in inner hair cells of the organ of Corti: synaptic expression and upregulation at the onset of hearing
Cysteine‐string protein is a vesicle‐associated protein that plays a vital function in neurotransmitter release. We have studied its expression and regulation during cochlear maturation. Both the mRNA and the protein were found in primary auditory neurons and the sensory inner hair cells. More impor...
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Published in | The European journal of neuroscience Vol. 15; no. 9; pp. 1409 - 1420 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Science, Ltd
01.05.2002
Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | Cysteine‐string protein is a vesicle‐associated protein that plays a vital function in neurotransmitter release. We have studied its expression and regulation during cochlear maturation. Both the mRNA and the protein were found in primary auditory neurons and the sensory inner hair cells. More importantly, cysteine‐string protein was localized on synaptic vesicles associated with the synaptic ribbon in inner hair cells and with presynaptic differentiations in lateral and medial olivocochlear terminals — the cell bodies of which lie in the auditory brainstem. No cysteine‐string protein was expressed by the sensory outer hair cells suggesting that the distinct functions of the two cochlear hair cell types imply different mechanisms of neurotransmitter release. In developmental studies in the rat, we observed that cysteine‐string protein was present beneath the inner hair cells at birth and beneath outer hair cells by postnatal day 2 only. We found no expression in the inner hair cells before about postnatal day 12, which corresponds to the period during which the first cochlear action potentials could be recorded. In conclusion, the close association of cysteine‐string protein with synaptic vesicles tethered to synaptic ribbons in inner hair cells and its synchronized expression with the appearance and maturation of the cochlear potentials strongly suggest that this protein plays a fundamental role in sound‐evoked glutamate release by inner hair cells. This also suggests that this role may be common to ribbon synapses and conventional central nervous system synapses. |
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Bibliography: | ark:/67375/WNG-RF1BHDVJ-R ArticleID:EJN1978 istex:1547A2E6B2C3BC42A686A722817AA083C493534C Present address Unité de Génétique des Déficits sensoriels, CNRS URA 1968, Institut Pasteur, 25–28 rue du docteur Roux 75724 Paris Cedex 15, France. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0953-816X 1460-9568 |
DOI: | 10.1046/j.1460-9568.2002.01978.x |