Low dose-dependent sub-chronic effect of HgCl2 on anxiety-related behavior of male Wistar rats subjected to the open field test. (a) Total amount time spent in the center (TCA); (b) Number of returns into center area of the arena in the open-field behavior apparatus (NRC); (c) Number of total squares (NTS). Data are expressed as mean ± SEM. The significance level is 0.05 with *p < 0.05, **p < 0.01, ***p < 0.001.