Spatial diversity in gene expression for VDCCγ subunit family in developing and adult mouse brains

The gamma subunit of voltage-dependent Ca2+ channels (VDCCs) is characterized by molecular diversity and regulation of AMPA-type glutamate receptors as well as VDCCs. In the present study, we examined expressions for the VDCC gamma l-8 subunit mRNAs in developing and adult mouse brains by in situ hybridization. In adult brains, the gamma 2 and gamma 7 subunit mRNAs were widely expressed in various grey matter regions with the highest level in cerebellar Purkinje cells and granule cells. The gamma 3 and gamma 8 subunit mRNAs predominated in the telencephalon, with the latter being at striking levels in the hippocampus. The gamma 4 subunit mRNA was enriched in the olfactory bulb, striatum, thalamus and hypothalamus. The gamma 5 subunit mRNA was abundant in the olfactory bulb, hippocampal CA2, thalamus, inferior colliculus and Bergmann glia. Transcripts of these subunits were detected in embryonic brains: some showed well-preserved spatial patterns (gamma 2, gamma 5, gamma 7 and gamma 8), while others underwent developmental up- (gamma 3) or down-regulation (gamma 4). In contrast, the gamma 1 and gamma 6 subunit mRNAs were negative or very low throughout brain development. Therefore, the present study has revealed spatial diversity in gene expression for individual VDCC gamma subunits, presumably reflecting functional diversity of this protein family and their differential involvement in neural function. (c) 2005 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.