Figure 2.

Treadmill exercise enhances the restoration of motor behavior in the MPTP-lesioned mouse model of PD.

Mice were administered MPTP in a series of 4 injections (total 80 mg/kg free-base) and subjected to treadmill running 5 days after the last injection. Panel A: The treadmill for mouse exercise. Panel B: Running velocity showing that MPTP parkinsonian mice (dark bars) achieve running behavior similar to saline (normal) mice after 3 weeks. Panel C: Analysis of striatal dopamine shows that parkinsonian mice do not have elevated levels of dopamine despite behavioral recovery. Panel D: Immunostaining for the striatal dopamine transporter (DAT) shows that exercised and recovered parkinsonian mice do not have elevated expression of DAT. Panel E: Fast-scan cyclic voltammetry shows increased dopamine release of remaining stores with exercise. Panel F: Dopamine D2 receptor ligand binding to [¹⁸F-fallypride] is restored with exercise in both mice (upper right image) and patients with Parkinson’s disease (lower panel).