TREADMILL PERFORMANCE OF MICE WITH CEREBELLAR LESIONS - 1 - PURKINJE-CELL DEGENERATION MUTANT MICE

The purpose of this study was to evaluate the sensorimotor skills of a spontaneous mouse mutant, Purkinje cell degeneration (PCD), marked by selective cerebellar cortical atrophy on a treadmill activated at 1 o f 2 speeds and at 1 of 3 slopes, requiring forward movements to avoid footshocks. There was no difference in latencies before falling from t he belt between PCD mutants and controls during acquisition. However, PCD mutants were impaired on the fast treadmill during retention, impl icating the cerebellum in the memory of a motor skill. During acquisit ion of the slow treadmill task at the 2 lowest slopes of inclination, PCD mutants spent more time walking than controls, an indication of a decreased ability of coordinating whole body movements. The same patte rn of higher walking time on the slow treadmill in PCD mutants was evi dent during retention. These results indicate that the cerebellar cort ex is involved in the acquisition and the retention of a task requirin g equilibrium.