Cytoarchitectonic abnormalities in cerebellum and hippocampal formation of beige mutant mouse

Abnormalities in the cerebellum and hippocampal formation of the beige mouse were revealed by histological and immunohistochemical examination. In the cerebellum, Purkinje cells and clusters of granule cells, plus an occasional Bergmann glia cell, were located ectopically in the molecular layer. In the hippocampus, ectopically situated pyramidal cell were found in the stratum oriens of area CA3. The infrapyramidal mossy fiber layer (IPMFL) was formed by fiber bundles emerging from two districtly separated areas of the dentate gyrus. The IMPFL was not compact, but appeared as clumps of scattered fiber bundles. The neuronal heterotopias and cytoarchitectonic disorganization observed in the beige mutant mouse cerebellum and hippocampus may prove to be very useful parameters in analyzing the relationship between the immune system and the development of the central nervous system.