GEI is age-dependent and motor learning-specific.

A. Motor learning in fixed-speed rotorod. Mice received VMT from 3 months old up to 5 months old. No significant difference was observed in either speed between trained control (n = 8) and trained tg mice (n = 11). B. Motor learning in accelerated-speed rotorod. Mice received VMT from 3 months old up to 5 months old. No significant difference was observed in either learning curve or each training session between trained control (n = 10) and trained tg mice (n = 9). C and D. Fear-conditioning. Neither two-way AVONA (transgene×VMT) nor the followed post-hoc analyses revealed a significant difference in freezing response in either the contextual conditioning (C) or cued conditioning (D) among the three groups of naïve control (n = 10), trained control (n = 7) and trained tg mice (n = 7). Imm: immediate; Condi: conditioning. E and F. Water maze test. Cross-sectional analysis of escape latency with one-way ANOVA indicated a highly significant learning improvement following trials in naïve control [F(5,54) = 6.412, p<0.001; n = 10), trained control [F(5,54) = 7.012, p<0.001; n = 10), and trained tg mice [F(5,60) = 7.908, p<0.001; n = 11)]. However, group comparison with the same two-way AVONA and post-hoc analyses did not reveal any significant difference in escape latency during the training sessions (E). Student's t test did not reveal a significant difference in the probe test between any two groups (F).