Experimental design and time-dependent changes in the physical and biochemical parameters in restraint stressed rats.
(A) Timeline diagram shows restraint stress induction protocol and behavioral tests. All rats were acclimatized for 1 week prior to 1-, 4-, or 8-week stress induction (black). One- and 4-week groups, were subjected to preceding stress-free period of 7 and 4 weeks (gray), respectively. Behavioral tests, i.e., elevated plus-maze (EPM), elevated T-maze (ETM), novel object recognition (NOR), Morris water maze (MWM), and forced swimming test (FST), were performed at the end of stress session. (B) Baseline body, (C) final body weight, (D) weight gain, (E) daily food intake, (F) dry weight of adrenal gland, and (G) dry adrenal gland weight normalized by body weight (BW) in 1-, 4-, and 8-week restraint stressed rats. (H) Glucocorticoid receptor (GR) protein expression normalized by β-actin in control and 1-week stressed rats. Inset: representative electrophoresis bands of GR and β-actin. (I–J) Serum and urinary corticosterone levels in 4-week stressed rats. Numbers of animals are noted in parentheses. *p < 0.05, **p < 0.01, ***p < 0.001 stress vs. control.