Immunohistochemical studies of the structural bases of inhibition in the central cerebellar nuclei in mice.

The distribution of glutamate decarboxylase-immunoreactive structures in the central nuclei of the cerebellum, its first afferent component, was studied at the light and electron microscope levels. Axosomatic, axodendritic, and axospinous synapses were detected, in which the presynaptic parts contained glutamate decarboxylase (GDC); this enzyme is involved in GABA synthesis. Additionally, these investigations revealed axoaxonal synapses in which both poles were GDC-reactive. The central nuclei of the cerebellum were found to have an intrinsic GABAergic system.