Fig. 6

Gut microbiota-mediated vitamin B₆ homeostasis regulated social behavior in EphB6-deficient mice. a–g Schematic of the injection of PLP (a). The 8-week-old male KO mice were injected with 1 mg PLP or saline intraperitoneally. After 1 h, mice were either sacrificed to detect PLP in plasma (b, n = 4 mice for each group) or subjected to self-grooming test (c, n = 10 mice for each group), olfactory habituation/dishabituation test (d, n = 8, 9 mice respectively), and three-chambered social approach task (e–g, n = 14 mice for each group). Different mice were used for different behavioral tests. h–j Schematic of the injection of PLP (h). Saline or PLP (1 mg, 2 mg, 5 mg per 0.2 mL) were injected intraperitoneally to 8-week-old male C57BL/6J mice. After 1 h, three-chambered social approach task was conducted (i, j, n = 10, 6, 10, 10 mice respectively). k–n Schematic of deficiency of vitamin B₆ in 6-week-old SPF male C57BL/6J mice (k). Normal diet contained 12 mg vitamin B₆ and vitamin B₆-deficient diet were provided for 6-week-old C57BL/6J mice for 2 weeks. The level of PLP in plasma of C57BL/6J was detected (l, n = 4 mice for each group) and three-chambered social approach task (m, n, n = 8, 8 mice respectively) were conducted. Data shown are mean ± SEM. Two-tailed unpaired student’s t test (b, c, f, g, l, n), one-way ANOVA (j), mixed design ANOVA with genotype as independent factor and stimuli/trials as repeated-measure factor (d). *p < 0.05; **p < 0.01; ***p < 0.001. WT EphB6^+/+ mice, KO EphB6^−/− mice, PLP pyridoxal 5′-phosphate, VB6 vitamin B₆. Statistical values are presented in Additional file 3: Table S2