Extended Data Fig. 9|. Effects of microbiome-dependent metabolites on thalamocortical axon outgrowth from GF explant co-cultures.

a, Axon number and b, axon length per 200 μm² surface area proximal to striatal explant (St) and from i) SPF thalamic explant (Th)+SPF St ii) ABX Th+ABX St, and iii) ABX Th+ABX St, supplemented with 1 nM, 100 nM, 10 μM of metabolites: trimethylamine N-oxide (TMAO), 5-aminovalerate (5-AV), imidazole propionate (IP), 3-indoxyl-sulfate (3-IS) or hippurate (HIP). (One-way ANOVA+Tukey’s, n= 14, 13, TMAO: 7, 6, 7, 5-AV: 3, 5, 7, IP: 5, 7, 7, 3-IS: 3, 7, 7, HIP: 6, 7, 8 explants). c, Axon number, and d, axon length per 200 μm² surface area proximal to hypothalamic explant (Hy) from i) SPF Th+SPF Hy), ii) ABX Th+ABX Hy, and iii) ABX Th+ABX Hy, supplemented with metabolites. (One-way ANOVA+Tukey’s, n=14, 10, TMAO: 6, 6, 7, 5-AV: 3, 5, 7, IP: 3, 6, 7, 3-IS: 3, 7, 5, HIP: 5, 7, 8 explants). e, E14.5 GF Th proximal to GF St treated with metabolites. Scale=250 μm. f, g, Axon number and h, i, axon length per 200 μm perimeter proximal to St (f, h) and Hy (g, i). (One-way ANOVA+Tukey’s, n=14, 15, 14, 13, 12, 12, 16 explants). Mean±SEM. *p<0.05, **p<0.01, ****p<0.0001