Behavioral analysis of FUS/TLS KO mice. (a) Spontaneous home cage activity of WT and TLS KO mice at 8 weeks. Total distance traveled (arbitrary units) in 7 days is shown. P = 0.0020 (n = 12 for WT, n = 11 for KO animals). (b) Total distance (P = 0.0062) and average speed of movements (P = 0.0045) of WT and KO animals in an open field test at 34 weeks (n = 12) (c) Fraction of time spent in open arms by WT and KO animals in an elevated plus maze test at 35 weeks. P = 0.0059 (unpaired two-tailed t-test, n = 12). (d) Results of a light-dark transition test of TLS WT and KO mice at 41 weeks. Mean ± SEM (n = 13 for WT, n = 21 for KO). KO mice spent longer time before entering into dark box (P = 0.034) and longer total time in the light box (P = 0.011), whereas their overall movement was not altered (P = 0.67). (e) Time spent on an accelerating rotarod by WT and KO animals at 39 weeks (P = 0.073, n = 13 for WT, n = 22 for KO animals). n.s.: not significant. Error bars represent SEM. Statistical significance was evaluated by two-tailed unpaired t-test.