Fig. 2.

GF mice display increased spontaneous motor activity. (a) Average distance travelled (metres) measured in 15-min time bins across a 90-min session in an open-field box. (Inset) Bars show time (seconds) spent in the centre during the initial 15 min of testing. (b) Average number of rears measured in 15-min bins across a 90-min session in an open-field box. (c) Representative tracks of movement patterns of SPF and GF mice at the 0–15, 46–60, and 76–90-min intervals of the 90-min open-field test session; distance travelled and rearing activity are shown in dark red and blue, respectively. All data (a–b) are presented as means (±SEM; n=10 per group). *p<0.05, **p<0.01 compared with SPF mice.