Immunohistochemical studies on the cellular localization of GABAA-receptors in explant cultures of rat central nervous system using a monoclonal antibody.

Explant cultures of rat spinal cord, brain stem and cerebellum were used to visualize GABAA-receptors by means of immunohistochemistry. For these studies we have incubated the cultures with the monoclonal antibody bd 17 against the beta-subunit of the GABAA/benzodiazepine/chloride channel complex. In spinal cord cultures, many interneurones were immunoreactive whereas only a small number of large neurones, probably motoneurones was specifically stained. In brain stem cultures, groups of large and medium-sized neurones showed immunoreactivity. In cultures of cerebellum, a great number of neurones was specifically stained. Granule cells showed the strongest immunoreactivity whereas other neurones, presumably Purkinje cells and interneurones, were only moderately stained. The immunoreactivity was mainly confined to the cell bodies of the neurones while their processes were only weakly or not stained. In contrast to neurones, no immunoreactivity could be detected on astrocytes.