A NOVEL, ABUNDANT SODIUM-CHANNEL EXPRESSED IN NEURONS AND GLIA

A novel, voltage-gated sodium channel cDNA, designated NaCh6, has been isolated from the rat central and peripheral nervous systems, RNase p rotection assays showed that NaCh6 is highly expressed in the brain, a nd NaCh6 mRNA is as abundant or more abundant than the mRNAs for previ ously identified rat brain sodium channels, in situ hybridization demo nstrated that a wide variety of neurons express NaCh6, including motor neurons in the brainstem and spinal cord, cerebellar granule cells, a nd pyramidal and granule cells of the hippocampus. RT-PCR and/or in si tu hybridization showed that astrocytes and Schwann cells express NaCh 6, Thus, this sodium channel is broadly distributed throughout the ner vous system and is shown to be expressed in both neurons and glial cel ls.