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Differential distribution of voltage‐gated calcium channels in dopaminergic neurons of the rat retina
Author(s) -
Witkovsky Paul,
Shen Changpeng,
McRory John
Publication year - 2006
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.20995
Subject(s) - biology , voltage dependent calcium channel , neuroscience , dopaminergic , axon , calcium , t type calcium channel , retina , calcium channel , axon terminal , r type calcium channel , dopamine , p type calcium channel , microbiology and biotechnology , medicine
We studied by immunocytochemistry and Western blots the identity and cellular distribution of voltage‐gated calcium channels within dopaminergic neurons of the rat retina. The aim was to associate particular calcium channel subtypes with known activities of the neuron (e.g., transmitter release from axon terminals). Five voltage‐gated calcium channels were identified: α1A, α1B, α1E, α1F, and α1H. All of these, except the α1B subtype, were found within dopaminergic perikarya. The α1B channels were concentrated at axon terminal rings, together with α1A calcium channels. In contrast, α1H calcium channels were most abundant in the dendrites, and α1F calcium channels were restricted to the perikaryon. The α1E calcium channel was present at such a low density that its cellular distribution beyond the perikaryon could not be determined. Our findings are consistent with the available pharmacological data indicating that α1A and α1B calcium channels control the major fraction of dopamine release in the rat retina. J. Comp. Neurol. 497:384–396, 2006. © 2006 Wiley‐Liss, Inc.