An ultrastructural study on the cerebellum of the brindled mouse.

Chronological morphological alterations of the cerebellum, with particular attention to the Purkinje cells, were investigated in the brindled mottled MObr mouse, a neurological mutant mouse with close clinical similarity to Kinky hair syndrome (KHS) in humans. Seven days post-natally, slight irregularity in the morphology of mitochondria of the Purkinje cell perikarya was the only significant difference between hemizygous MObr mice and litter mate controls. With advancing age the mitochondrial change became more pronounced gradually in the former, not only in the perikarya but also in the dendrites. However, by day 31 or later the mitochondrial change subsided gradually and by day 91, the mitochondria in the majority of Purkinje cells became indistinguishable from those of littermate controls. Despite the extensive mitochondrial alteration, degeneration and necrosis of Purkinje cells were rather mild. Degeneration of white matter was quite conspicuous in the mutant mouse older than 31 days. These morphological changes of the cerebellum are compared with those of other neurological mutant mice, Nervous and Purkinje cell degeneration, and with KHS in humans.