Absence of an association between motor coordination and spatial orientation in lurcher mutant mice.

Lurcher mutant mice were impaired in spatial orientation and motor coordination in comparison to normal mice. Both groups improved across days in both invisible and visible water maze platform conditions. Contrary to normal mice, lurcher mutants did not improve over days in terms of the time taken to reach a side-bar in a motor coordination test, an indication of defective motor learning. However, lurchers were able to stay on the bar longer across days. These results indicate that motor learning deficits in this cerebellar-damaged animal are not absolute but dependent on the type of measurement attempted. There was no correlation between motor coordination and spatial orientation for normal mice. A similar absence of correlation was noted for lurcher mutants, except for falling latencies in the coat-hanger test during the middle of training.