An unsteady platform test for measuring static equilibrium in mice

An unsteady platform test is presented in which mice must remain still on a narrow surface in order to prevent a fall. The mouse spontaneous mutation, Lurcher, causing cerebellar cortical degeneration, was evaluated on the unsteady platform, requiring balance in a stable body position (static equilibrium), as opposed to the stationary beam test, in which the animals are free to move on a larger surface (dynamic equilibrium). Lurcher mutants spent less time and had a higher number of slips than controls on the unsteady platform. In contrast, Lurcher mutants did not differ from controls for latencies before falling and distance travelled on the stationary beam. These results are discussed in terms of the possible involvement of two cerebellar circuits in motor Control. (C) 1999 Elsevier Science B.V. All rights reserved.