Reconsolidation of rotarod-running skill requires protein synthesis. Naïve rats were trained one trial each day for 7 consecutive days. Surgery was performed on day 4 after the last training trial. Rats were retrained one trial on day 4 after the surgery, and then received a retrieval trial (Test 0) to reactivate the running-skill memory. (A) Rats were infused with anisomycin at 0, 2 or 6 h after Test 0, respectively. They were tested one trial each day for the subsequent 2 days (Test 1 and Test 2). Rats in post-0 group (n = 9) exhibited a deficient performance in Test 1 and the deficit was partially recovered in Test 2. Rats in post-2 group (n = 7) exhibited a normal performance in both Test 1 and 2. Rats in post-6 group (n = 8) showed a deficit in the task performance in both Test 1 and 2. * p < 0.05, **p < 0.01 vs. Test 0, paired t-test. (B) Rats were infused with anisomycin at 0, 0.5, 2, 4, 6, or 12 h after Test 0, respectively. They received a retention test at 6 h after anisomycin infusion (Test 1) and a second retention trial 24 h later (Test 2). Rats in post-0, post-6, and post-12 groups exhibited an impaired performance in Test 1. The deficient performance of the post-0 group was recovered in Test 2. * p < 0.05 vs. Test 0, paired t-test. ** p < 0.01 vs. Test 0, paired t-test. ns: not significant. n = 12, 8, 8, 9, 8, 7 rats for the post-0, post-0.5, post-2, post-4, post-6 and post-12 groups, respectively. Data are expressed as means ± SEM.