Pathological effects of in utero methylmercury exposure on the cerebellum of the golden hamster. II. Residual effects on the adult cerebellum

The long-term effects of prenatal methylmercury exposure were studied in the golden hamster (Mesocricetus auratus). Pregnant animals were given either 10 mg/kg methylmercury on gestational day 10 or 2 mg/kg on gestational days 10-15. Animals from treated and control litters were sacrificed as adults and cerebella examined by light and electron microscopy. Focal areas of astrogliosis were observed in the molecular layer of treated animals. Sequellae of previous injury, characterized primarily by abundant residual bodies, were observed in the perikarya and dendrites of granule and Purkinje neurons. Degenerative change of myelinated axons was observed. Possible hypotheses for continued neuronal degeneration in prenatally exposed animals are discussed.