FIGURE 5

FIGURE 5

Behavior detection of CONR larvae, germ-free (GF) larvae and germ-free larvae mono-associated with 10⁴ and 10⁶ CFU/ml E. coli DH5α. (A) Traveling distance was recorded every minute, testing for 48 h in total and traveling distance during 5 h when the behavior of all zebrafish was relatively stable is shown. (B) Mean traveling distance of each group during the 48 h of testing. (C) The distance that CONR), germ-free (GF) and germ-free (GF) mono-associated zebrafish moved in slow (<8 mm/s), middle (>8 and <20 mm/s) or fast (>20 mm/s) locomotion during 48 h of testing. (D) The expression levels of 5-hydroxytryptamine synthesis related genes htr1aa, tph1a, slc4a6a, mao, and bdnf. All data (B–D) were presented as means ± SEM. Different letters indicate statistically significant differences among groups (p < 0.05).