Cerebellar benzodiazepine receptor distribution: an autoradiographic study of the normal C57BL/6J and Purkinje cell degeneration mutant mouse.

The distribution of [3H]flunitrazepam binding sites in the cerebella of normal mice and Purkinje cell degeneration mutant mice was studied by light microscopic autoradiography. In the cerebellar cortex of normal mice, a high density of [3H]flunitrazepam binding was observed over the molecular layer, an intermediate density over the Purkinje cell layer and a low density over the granule cell layer; the white matter was devoid of labeling. The deep cerebellar nuclei were labeled to an intermediate density. In the 54-day-old Purkinje cell degeneration mutant cerebellum, which is depleted of Purkinje cells, a 36% reduction in labeling density of the cerebellar cortex was observed. The density was reduced by approximately equal amounts in both the molecular and granule cell layers; labeling in the deep cerebellar nuclei was, however, substantially increased.