CAM-I MESSENGER-RNA IS LOCALIZED TO APICAL DENDRITES DURING POSTNATAL-DEVELOPMENT OF NEURONS IN THE RAT-BRAIN

In the rat, a single calmodulin (CaM) protein is encoded by three sepa rate genes which produce five different transcripts. The significance of the multiple CaM genes is not known; however, individual CaM transc ripts could be targeted to specific intracellular sites, In this repor t, the cellular distribution of CaM I mRNAs was analyzed in the postna tal rat brain, The 4.0-kb CaM I transcript was present in neuronal cel l bodies and also localized to apical dendritic processes. In cerebral cortical neurons, the 4.0-kb CaM I mRNA was detected in apical dendri tes at postnatal day (PD) 5 to 15, In hippocampal neurons, this CaM me ssage was present in dendritic processes from PD 5 to 20, whereas in P urkinje neurons it was detected in dendrites at PD 15 and 20, The pres ence of the 4.0-kb CaM I mRNA in dendrites of the rat brain supports t he notion of targeting transcripts derived from the CaM multigene fami ly to discrete intracellular destinations. (C) 1996 Wiley-Liss, Inc.