REGIONAL AND CELLULAR EXPRESSION PATTERNS OF 4 K-RNAS IN THE ADULT-RAT BRAIN( CHANNEL MESSENGER)

Potassium (K+) channels are involved in the modulation and fine tuning of the excitable properties of neurons and glia in the nervous system . In the present report, in situ hybridization histochemistry was used to determine the regional and cellular distribution patterns in the a dult rat brain of four mRNAs encoding subunits of voltage-gated K+ cha nnels. These are Kv1.1, Kv1.6, K13 and 1K8. All K+ channels examined s howed distinct yet overlapping expression patterns. Expression of Kv1. 1 mRNA was high in cells of certain motor-related structures of the br ainstern Kv1.6 mRNA expression was observed in cerebellar Purkinje cel ls and in various olfactory and amygdaloid structures. K13 was the onl y mRNA expressed in both neuronal and non-neuronal cell populations, i ncluding the cells of choroid plexus and pia. 1K8 expression was obser ved only in the forebrain structures. In many brain regions, mRNAs for Kv1.1 and Kv1.6, both encoding K+ channel subunits belonging to the S haker subfamily, were co-expressed, a necessary condition for heteromu ltimer formation.