[Light- and electron microscopy studies on the cerebellum in 12-day-old rats after treatment with 6-aminonicotinamide (6-AN)].

Light- and electron-microscopie studies were performed in glia cells and neurons of the cerebellum of 12-day-old rats until 48 following intraperitoneal application of 8 mg/kg 6-aminonicotinamide (6-AN), an antimetabolite of nicotinamide that inhibits the oxidative pentose-phosphate pathway. Particularly sensitive were the neuroblasts of the external granular layer. The migration of the neuroblasts was clearly reduced. Parts of the internal granular layer were damaged, while the Purkinje cells and astrocytes remained unchanged. Oligodendrocytes and astrocytes showed vacuolar degeneration. Swelling of the myelin sheath occurred in the form of a status spongiosus. 48 h after 6-AN injection some mitoses and phagocytic cells were found in the internal granular layer.