Differential Localization of mRNAs for Mammalian trps, Presumptive Capacitative Calcium Entry Channels, in the Adult Mouse Brain

Mammalian homologues for Drosophila trp are likely to be candidates for capacitative calcium entry channels. By in situ hybridization histochemistry, we have demonstrated that the mRNAs for four species of the mouse homologues (Mtrps-1, -3, -4, -6) were differentially expressed in the adult mouse brain. Mtrp-1 mRNA was expressed widely throughout the gray matters, while the expression for Mtrp-3 was dominant in the cerebellar Purkinje cells, the olfactory mitral cells and the striatal large-sized intrinsic neurons. Mtrp-4 mRNA was evident in the olfactory bulb, the septum, the hippocampal neuronal layers, and the cerebellar granule cell layer, while the expression for Mtry-6 was rather confined to the dentate granule cell layer. Their differential localization suggests that the individual homologues exert their functions in region-specific and neuron-specific manners in the calcium signaling.