(A) Mice were trained on the rotarod with either saline or L-DOPA (25 mg/kg) for 5 sessions (sessions 1–5). After a 3-day treatment discontinuation break the mice were again tested without treatment (session 6). After one refresher training session on either saline or L-DOPA (session 7, not shown) and a 5-day treatment discontinuation break, mice were run for 3 sessions without any treatment (sessions 8–10). Top panel shows latency to fall for each trial and lower panel shows the average latency to fall during each session. (N = 6 per genotype/treatment). (B) Wild-type C57BL/6 mice were trained on the rotarod for 12 days without injections (last training session, session 12, is shown). Animals were then given a D2 blocker (eticlopride, 0.16 mg/kg) and tested on the rotarod for 5 consecutive days (sessions 13–17).