Multiple gabaa receptor α subunit mRNAs revealed by developmental and regional expression in rat, chicken and human brain

Abstract

GABA_A receptor α subunit transcripts were detected by Northern analysis of rat, chicken and human brain mRNA using a series of ³² P-labelled antisense RNA probes derived from human α₁ subunit cDNAs. These α subunit mRNAs differ in their distribution among various brain regions in the rat and at least one species is detected primarily in fetal brain. GABA_A receptor α_a subunit probes encoding the putative extracellular domain detect at least five α subunit transcripts in rat brain, whereas probes encoding the putative intracellular domain detect only two mRNAs. These data suggest the presence in brain of multiple GABA_A receptor α subunits having homologous extracellular domains and whose expression is regionally and developmentally regulated. These α subunit transcripts may encode proteins that comprise GABA_A isoreceptors differing in their pharmacological and physiological properties.