Figure 4.

IB2−/− mice show impaired motor performance and learning. IB2+/+ and IB2−/− mice were tested for baseline motor performance and learning on an accelerating rotarod for 4 consecutive days and scored for rod revolution speed at time of fall-off. Data are shown for males of mixed background (A), females of mixed background (B), and females of 129/SvEv background (C). For all cohorts, IB2+/+ mice performed better at initial testing than IB2−/− mice, and only IB2+/+ mice improved significantly over the 4 d testing period. D, Grip strength of IB2+/+ and IB2−/− female mice on 129/SvEv background. Forepaw grip strength while resisting pull-off from sensor bar was monitored between 3 and 5 weeks of age. IB2−/− animals showed mildly delayed strength acquisition, but did not differ significantly from IB2+/+ mice by week 5.