An increased expression of Ca2+ channel α1A subunit immunoreactivity in deep cerebellar neurons of rolling mouse Nagoya

Rolling mouse Nagoya (RMN) is an ataxic mutant and carries a mutation in the gene coding for the alpha (1A) subunit of the P/ Q-type Ca2+ channel. We examined the immunohistochemical expression of the alpha (1A) subunit in deep cerebellar nuclei of RMN. The antibody used recognized residues 865-883 of the mouse alpha (1A) subunit not overlapping the altered sequences in RMN. In RMN, many neurons exhibited definite a1A subunit-staining in the medial nucleus, interposed nucleus, and lateral nucleus of deep cerebellar nuclei. The number of positive neurons in these nuclei was significantly higher in RMN than in controls. Increased expression of the alpha (1A) subunit in deep cerebellar neurons might compensate for the altered function of the P/Q-type Ca2+ channel of RMN. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.