Statistical analysis

Statistical analyses were performed with Matlab (The Mathworks, Inc., USA) and Prism (Dotmatics, USA). For variables with more than two levels (groups), such as the main inter-group results (sham vs. low vs. high power PBM), first the normality of data set was confirmed using the Lilliefors test. Given data being normally distributed, one-way ANOVA (analysis of variance) was performed. For variables with two levels (such as baseline vs. endpoint behavioral comparison) either paired Student’s t-test or—for non-normal data according to the Lilliefors test–Wilcoxon’s signed rank test was used. The n values can be found in the figure legends and correspond to the number of mice analyzed. Results are presented as mean ± SEM (standard error of the mean) unless stated otherwise. Statistical differences were considered significant at p < 0.05; denoted by one asterisk in figures; two of three asterisks denote p < 0.01 or p < 0.001, respectively.