EFFECTS OF NERVOUS MUTATION ON PURKINJE-CELL COMPARTMENTS DEFINED BY ZEBRIN-II AND 9-O-ACETYLATED GANGLIOSIDES EXPRESSION

The cerebellum is organized into a series of parasagittally aligned ba nds which are well delineated in the adult mouse by the largely comple mentary immunostaining of Purkinje cell groups with the monoclonal ant ibodies Zebrin II (ZII; antigen: aldolase C) and P-path (antigen: 9-O- acetyl gangliosides). We examined the effect of nervous mutation on co mpartmental organization using these markers and an antibody to calbin din. In nervous mutant, up to 90% of Purkinje cells die in late postna tal development. The size of the cerebellum is about half that of norm al, and caudal lobules appear to decrease in size more than anterior o nes. Surviving Purkinje cells corresponded to P-path positive ones tha t were concentrated in two bilateral bands in the vermis and in medial portions of the hemispheres. Only small numbers of ZII positive cells remained, confirming the report by Wassef et al. with Zebrin I antibo dy. They were primarily located in caudal lobules IX, X and a portion of lobule IV, paraflocculus and flocculus, and their immunoreactivity was weak compared to that of normal. ZII positive cells are dominant i n these caudal lobules, while P-path positive cells dominate in rostra l lobules in normal mice, and the similar tendency remains in mutant. Thus, the nervous gene action respects not only sagittal compartments delineated by two antibodies, but also rostro-caudal gradient. The cau se of the dominant survival of P-path positive cells awaits future stu dy.