In the present work we describe the cellular localization of TRPC3 in non-excitable cells as compared to the neurons in normal rat brain. We performed a double labeling study for TRPC3 and one of the following cell-specific markers: mouse anti-glial fibrillary acidic protein (GFAP) for astrocytes; mouse anti-RIP for oligodendrocytes, or mouse anti-OX42 for microglia, or mouse anti-NeUN for neuronal nuclei or mouse anti-tyrosine hydroxylase (TH) for detection of dopaminergic neurons of the substantia nigra. Our double label immunofluorescence study showed that that TRPC3 is mainly localized in oligodendrocytes. These result were confirmed by the electron microscopy study, which showed TRPC3 immunoreactivity in oligodendrocytes. Consistent with the evidence that calcium homeostasis is important to oligodendrocytes for development, myelination, and demyelination [Microsc. Res. Tech. 52 (2001) 672], we can speculate that the distribution of TRPC3 in oligodendrocytes plays a role in myelination and or demyelination processes.