Fig. 6

Transplantation of microbiota from control mice to p-Cresol-treated mice restores social behavior deficits, VTA dopamine neurons excitability, and fecal p-Cresol levels. A Timeline of the transplantation procedure with fecal microbiota from control donor mice (FMT^Control) to control or p-Cresol-treated recipient mice. B–G Dyadic social interaction test pre-FMT^Control and 3 weeks post-FMT^Control (n = 15/group pre-FMT, n = 14/group post-FMT): B Total time spent in social contact; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) < 0.0001, p (Treatment × FMT^Control) < 0.0001; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. C Number of nose contacts; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) = 0.0022, p (Treatment × FMT^Control) < 0.0001; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. D Mean duration of each nose contact; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) < 0.0001, p (Treatment × FMT^Control) < 0.0001; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. E Number of paw contacts; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) = 0.0221, p (Treatment × FMT^Control) < 0.0001; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. F Mean duration of each paw contact; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) < 0.0001, p (Treatment × FMT^Control) < 0.0001; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. G Number of followings; 2-way ANOVA: p (Treatment) = 0.0020, p (FMT^Control) = 0.0516, p (Treatment × FMT^Control) = 0.0002; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. H–J Three-chamber test pre-FMT^Control and 3 weeks post-FMT^Control (n = 15/group pre-FMT, n = 14/group post-FMT): H Sociability index pre-FMT^Control and 3 weeks post-FMT^Control; 2-way ANOVA: p (Treatment) = 0.0004, p (FMT^Control) < 0.0001, p (Treatment × FMT^Control) = 0.0032; Šidák’s post hoc tests for treatment effect: ****p < 0.0001 for pre-FMT groups, p > 0.05 for post-FMT groups. I Time in close contact with the mouse interactor or the toy mouse post-FMT^Control; 2-way ANOVA: p (Treatment) = 0.8480, p (Preference) < 0.0001, p (Treatment × Preference) = 0.6498; Šidák’s post hoc tests for mouse vs. toy preference: ****p < 0.0001. J Mean duration of each nose contact with the mouse interactor or toy mouse post-FMT^Control; 2-way ANOVA: p (Treatment) = 0.9067, p (Preference) < 0.0001, p (Treatment × Preference) = 0.8713; Šidák’s post hoc tests for mouse vs. toy preference: ****p < 0.0001. K, L Motor stereotypies pre-FMT^Control and 3 weeks post-FMT^Control (n = 15/group pre-FMT, n = 15/group post-FMT): K Number of head shakes; 2-way ANOVA: p (Treatment) = 0.0021, p (FMT^Control) = 0.0715, p (Treatment × FMT^Control) = 0.2334; Šidák’s post hoc tests for treatment effect: **p < 0.01 for pre-FMT groups, p > 0.05 for post-FMT groups. L Number of circling events; 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) = 0.1133, p (Treatment × FMT^Control) = 0.5555; Šidák’s post hoc tests for treatment effect: *p < 0.05, ***p < 0.001. M PCA plots of behavioral scores recorded in the dyadic social interaction test and direct monitoring of motor stereotypies pre-FMT^Control and 3 weeks post-FMT^Control (B–G, K, L, Additional file 1: Fig. S6H-K); ellipses of the 95% confidence intervals are indicated for each group (n = 15/group pre-FMT, n = 14/group post-FMT). N, O Electrophysiological recordings of dopamine neurons activity in the VTA 3 weeks post-FMT^Control: N Representative traces of dopamine neurons activity in patch-clamp experiments performed post-FMT^Control after a 200-pA current injection. O Number of action potentials evoked by different current injection steps (n = 3 animals/group, 10 cells recorded/animal); 2-way ANOVA: p (Treatment) = 0.5474, p (Current) < 0.0001, p (Treatment × Current) = 0.3640; Šidák’s post hoc tests for treatment effect: p > 0.05. P Fecal levels of p-Cresol pre-FMT^Control and 3 weeks post-FMT^Control (n = 15/group pre-FMT, n = 14/group post-FMT); 2-way ANOVA: p (Treatment) < 0.0001, p (FMT^Control) = 0.0044, p (Treatment × FMT^Control) = 0.0011; Šidák’s post hoc tests: ****p < 0.0001; ***p < 0.001. B–L, P Data are presented as dot-plots featuring means ± SD. O Data are presented as means ± SD