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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-5-25
pubmed:abstractText
Voltage-gated calcium channels are important for neurotransmission at the level of inner hair cells (IHCs) and outer hair cells (OHCs). These channels open when mechanical stimulation depolarises the hair cell membrane and the resulting calcium influx triggers neurotransmitter release. Voltage-gated calcium channels expressed in hair cells are known to be of the L-type with a predominance of the Ca(v)1.3 subunit. The present study describes the developmental expression of the Ca(v)1.3 protein in the cochlea and the vestibular system using immunohistochemical technique. In the adult organ of Corti (OC), Ca(v)1.3 was localized in both sensory and non-sensory cells with a more intense expression in IHCs and Deiters cells when compared to OHCs. In both hair cell types, immunoreactivity was observed in the apical pole, basolateral membrane and at the basal pole (synaptic zone). Similar results were obtained in the vestibular organs. During development, Ca(v)1.3 immunoreactivity was observed in the cochlea as early as embryonic day 15, with expression increasing at birth. At these early stages of cochlear development, Ca(v)1.3 was expressed in all cell types surrounding the scala media. In the OC, the labeling was observed in IHCs, OHCs and supporting cells. The Ca(v)1.3 expression reached an adult-like pattern by the end of the second postnatal week. The present findings suggested that, in addition to their implication in hair cells synaptic transmission, Ca(v)1.3 calcium channels also play an important role in vesicle recycling and transport, as suggested by their extrasynaptic location at the apical pole of the hair cells. The Ca(v)1.3 channels in Deiters cells could participate in active calcium-induced changes in micromechanics of these supporting cells. An early expression during development suggested that these calcium channels are in addition important in the development of the cochlear and vestibular sensory epithelium.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0165-3806
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
150
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-75
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Developmental expression of Ca(v)1.3 (alpha1d) calcium channels in the mouse inner ear.
pubmed:affiliation
Laboratoire de Biologie Cellulaire de l'Audition, EA3665 Université Victor Segalen Bordeaux 2, Hôpital Pellegrin, PQR3, INSERM EMI 99-27, 33076 Bordeaux, France. azhafidi@univ-bpclermont.fr
pubmed:publicationType
Journal Article, Comparative Study