The GABAA receptor gamma 1 subunit is expressed by distinct neuronal populations

The distribution of GABAA receptor gamma 1 subunit was examined in the rat central nervous system using in situ hybridization histochemistry. The gamma 1 subunit was expressed in relatively limited areas compared to other subunits investigated previously. The brain regions strongly expressing this subunit were the septum, globus pallidus, bed nucleus of the stria terminalis, hypothalamic periventricular nucleus, supraoptic nucleus, medial and central nuclei of the amygdaloid complex, medial part of the medial geniculate body, substantia nigra pars reticulata, interpeduncular nucleus, lateral parabrachial nucleus, Purkinje cell layer of the cerebellum, and inferior olivary nucleus. This relatively limited expression implies a possible role of gamma 1 subunit in relation to some specific neuronal circuit.