Fig. 1.

Germ-free (GF) mice display increased sociability. (a) Bars show time (seconds) spent in the different chambers during the social approach session by specific pathogen-free (SPF) and GF mice. (b) Bars show time (seconds) spent interacting with the stimulus mouse or in close proximity to the novel object. (c) Bars show sociability indexes (percentage) of SPF and GF mice. (d) Bars show time (seconds) spent in self-grooming by SPF and GF mice. All data (a–d) are presented as means (±SEM; n=10 per group). *p<0.05, *p<0.01, ***p<0.001 compared with SPF mice.