Figure 6.

Rotorod performance of mice aged 4 (n = 28), 12 (n = 27), and 18 (n = 28) months, at 15 or 25 revolutions per minute (rpm), over three test days. Learning in the cerebellar-dependent rotorod task is impaired in older mice at both 15 and 25 rpm. The 15-rpm procedure is sensitive to deficits found in 18-month-old mice. These mice do not perform similarly to 4 month olds until the third day of training. The 25-rpm procedure is sensitive to deficits found in both 12- and 18-month-old mice. Learning, nonetheless, is expressed by all age groups in both procedures.