Developmental expression of voltage-gated potassium channel beta subunits

Expression of potassium channel beta subunits (Kv beta) was determined in t he developing mouse CNS using an antiserum against an amino acid sequence p resent in the C-terminus of Kv beta 1, Kv beta 2, and Kv beta 3. Using the anti-Kv beta antiserum, we determined that Kv beta expression is restricted to the spinal cord and dorsal root ganglia in the embryonic CNS. At birth, Kv beta expression is detected in brainstem and midbrain nuclei, but was n ot detected in the hippocampus, cerebellum or cerebral cortex. During the f irst postnatal week, Kv beta expression is present in hippocampal and corti cal pyramidal cells and in cerebellar Purkinje cells. Expression of Kv beta subunits reaches adult levels by the third postnatal week in all of the br ain regions examined. A rabbit antiserum directed against a unique peptide sequence in the N-terminus of the Kv beta 1 protein demonstrates that this subunit displays a novel expression pattern in the developing mouse brain. Kv beta 1 expression is high at birth in all brain regions examined and dec reases with age. In contrast, Kv beta 2 expression is low at birth and incr eases with age to reach adult levels by the third postnatal week. These fin dings support the notion that the differential regulation of distinct potas sium channel beta subunits, in the developing mouse nervous system, may con fer the functional diversity required to mediate both neuronal survival and maturation. (C) 1999 Elsevier Science B.V. All rights reserved.