GABAERGIC NEURONAL CIRCUITS IN THE CEREBELLUM OF THE DOGFISH SCYLIORHINUS-CANICULA (ELASMOBRANCHS) - AN IMMUNOCYTOCHEMICAL STUDY

The presence of GABAergic cells and fibres in the corpus cerebelli and auricles of a dogfish, Scyliorhinus canicula, was studied with immuno cytochemistry. In both locations, two types of GABA-immunoreactive (GA BA-ir) neurons were observed: stellate cells in the molecular layer an d Golgi cells in the granular layer. Stellate cell axons gave rise to numerous GABA-ir boutons distributed throughout the molecular layer an d a smaller number of boutons which contacted Purkinje cell perikarya. No GABA-ir baskets around Purkinje cells were observed. Golgi cells o f the granular layer gave rise to numerous GABA-ir boutons which were located around cerebellar glomeruli. Purkinje cell perikarya and their axon terminals in the cerebellar nucleus were not GABA-immunoreactive , These findings are discussed in terms of the phylogeny of cerebellar circuits.