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Voltage‐gated calcium channels in developing GnRH‐1 neuronal system in the mouse
Author(s) -
Toba Yoko,
Pakiam Jennifer G.,
Wray Susan
Publication year - 2005
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2005.04194.x
Subject(s) - olfactory epithelium , voltage dependent calcium channel , calcium channel , medicine , biology , endocrinology , vomeronasal organ , axon , gonadotropin releasing hormone , neuroscience , olfactory system , calcium , microbiology and biotechnology , hormone , luteinizing hormone
Migration of gonadotropin‐releasing hormone‐1 (GnRH‐1) neurons from the nasal placode into the central nervous system occurs in all vertebrates. This study characterizes the expression of L‐ and N‐type voltage‐gated calcium channels (VGCCs) in migrating GnRH‐1 neurons in mice. Class C (L‐type) and class B (N‐type) VGCGs were detected in GnRH‐1 cells and cells in the olfactory and vomeronasal epithelium during prenatal development. This expression pattern was mimicked in a nasal explant model known to retain many characteristics of GnRH‐1 development in vivo . Using this in vitro system, perturbation studies were performed to elucidate the role of VGCCs in GnRH‐1 neuronal development. This report shows that olfactory axon outgrowth and GnRH‐1 neuronal migration are attenuated when nasal explants are grown in calcium‐free media, and that this effect is temporally restricted to an early developmental period. Blockade of either the L‐ or the N‐type channel did not alter GnRH‐1 cell number or overall olfactory axon outgrowth. However, blockade of N‐type channels altered the distribution of GnRH‐1 neurons in the periphery of the nasal explants. In these explants, more GnRH‐1 neurons were located proximal to, and fewer GnRH‐1 neurons distal to, the main tissue mass, suggesting a general decrease in the rate of GnRH‐1 neuronal migration. These results indicate that extracellular calcium is required for initiating GnRH‐1 neuronal migration and that these events are partially dependent on N‐type VGCC signals.