Figure 2.

Behavior tests of the CUMS rats intravenously administrated with dose gradients of propionate. Body weight (a), sucrose preference rate (b), time spent immobile in tail suspension test (c), time spent immobile in forced swimming test (d), and indices of open field test (e–h) were recorded or tested with the protocol described in the Material and Methods section at the time point shown in Fig. 1. The data are shown as mean ± S.E.M, with shapes indicating the corresponding value from each rat. A nonparametric t-test was applied for between-group statistical significance. *P < 0.05, **P < 0.01, and ***P < 0.001, ****P < 0.0001.