title: Localization of the calcium channel subunits Cav1.2 (alpha1C) and Cav2.3 (alpha1E) in the mouse organ of Corti.
abstract: Voltage-activated Ca2+ channels play an important role in synaptic transmission, signal processing and development. The immunohistochemical localization of Cav1.2 (alpha1C) and Cav2.3 (alpha1E) Ca2+ channels was studied in the developing and adult mouse organ of Corti using subunit-specific antibodies and fluorescent secondary antibodies with cochlear cryosections. Cav1.2 immunoreactivity has been detected from postnatal day 14 (P14) onwards at the synapses between cholinergic medial efferents and outer hair cells as revealed by co-staining with anti-synaptophysin and anti-choline acetyltransferase. Most likely the Cav1.2 immunoreactivity was located presynaptically at the site of contact of the efferent bouton with the outer hair cell which suggests a role for class C L-type Ca2+ channels in synaptic transmission of the medial efferent system. The localization of the second Ca2+ channel tested, Cav2.3, showed a pronounced change during cochlear development. From P2 until P10, Cav2.3 immunoreactivity was found in the outer spiral bundle followed by the inner spiral bundle, efferent endings and by medial efferent fibers. Around P14, Cav2.3 immunoreactivity disappeared from these structures and from P19 onwards it was observed in the basal poles of the outer hair cell membranes.
authors.affiliation: Institute of Physiology II and Department of Otolaryngology, Tuebingen Hearing Research Centre (THRC), University of Tuebingen, Tuebingen, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Waka
authors.forename: M
authors.initials: M
authors.lastname: Knipper
authors.forename: J
authors.initials: J
authors.lastname: Engel
mesh_terms: D000818:Animals; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure*; D002531:Cerebellum / Q000378:metabolism / Q000648:ultrastructure; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004594:Electrophysiology; D005455:Fluorescent Antibody Technique; D006199:Hair Cells, Auditory, Inner / Q000378:metabolism / Q000648:ultrastructure; D018072:Hair Cells, Auditory, Outer / Q000378:metabolism / Q000648:ultrastructure; D007150:Immunohistochemistry; D051379:Mice; D016900:Neurofilament Proteins / Q000378:metabolism; D009925:Organ of Corti / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure*; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D016708:Synaptophysin / Q000378:metabolism
chemical_list: C498916:Cacna1e protein, mouse; D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; C419385:L-type calcium channel alpha(1C); D016900:Neurofilament Proteins; D016708:Synaptophysin; D002795:Choline O-Acetyltransferase