A simple method to measure stride length as an index of nigrostriatal dysfunction in mice.

Reduced stride length characterizes Parkinsonian gait. We aimed to demonstrate that it could be measured simply and reliably in mice by pawprints and used as an index of basal ganglia dysfunction. In C57BL/6 mice, stride length measurements proved to be consistent across measurements and experimenters. It was slightly lower in the hindlimbs and was correlated to femur size and animal velocity. Dopamine depletion by reserpine and striatal dopamine receptor blockade by haloperidol resulted in reduced mean stride length in four limbs. Significant forelimb/hindlimb difference was also observed both in mice with 3-nitropropionic acid (3-NP) induced striatal lesions and in those with MPTP-induced nigral cell loss. Reduction of hindlimb stride length was correlated significantly with the magnitude of cell loss, either in the substantia nigra or in the lateral mid-striatum. Stride length is, therefore, a simple method to obtain an index of motor disorders due to basal ganglia dysfunction in mice.