Abnormal synaptic organization between granule cells and Purkinje cells inthe new ataxic mutant mouse, pogo

The pogo mouse is a new ataxic mutant derived from the Korean wild mouse. T he pathological manifestations include difficulty in maintaining normal pos ture and the inability to walk straight. The ataxia becomes apparent at abo ut 2 weeks of age. Electron microscopic studies of the pogo/pogo homozygous cerebellum, revealed that the ectopic spines emanating from the primary de ndrite of Purkinje cells were observed. Major difference between pogo/pogo homozygous and non-affected pogo/+ heterozygous was the synaptic organizati on of the molecular layer. Parallel fiber varicosities were larger than nor mal and a single fiber often established synaptic contacts with up to four dendritic spines of a Purkinje cell. This correlation between the presence of altered synaptic organization in the cerebellum and ataxia in pogo/pogo mutant mice warrants further investigation. (C) 2000 Published by Elsevier Science Ireland Ltd.