A, In 12 week gene-on—4 week gene-off mice, Rotarod performance was not improved compared with the performance level of 12 week gene-on and 16 week gene-on mice. Error bars indicate SEM. B, In 12 week gene-on—8 week gene-off and 12 week gene-on-12 week gene-off animals, their performance on the Rotarod improved above the performance level of 20 week gene-on and 24 week gene-on mice, but did not reach the performance level of 19-week-old wild-type nontransgenic FVB/N animals.