The effect of acute swimming stress, corticosterone, dexamethasone, and fludrocortisone on anxiety-like behavior in mice

Introduction: Acute swimming stress (ASS) exerts a biphasic effect on anxiety-like behavior (ALB) in mice, inducing an enhancement and a subsequent decrease in ALB 1 h and 24 h after exposure, respectively. Presumably, this effect may be caused by the activation of mineralocorticoid and glucocorticoid receptors, both during the immediate response to acute stress and after its termination at the phase of adaptive changes. Aim of the Research: Comparative study of the effects of acute swimming stress, corticosterone, dexamethasone, and fludrocortisone on ALB in mice 1 h and 24 h after stress exposure or administration of the studied substances. Materials and Methods: To model ASS in adult male ICR mice, the forced swimming test (FST) was employed. ALB was assessed in mice in the open field test 1 h and 24 h after FST or systemic administration of corticosterone (20 mg/kg), dexamethasone (10 mg/kg), and fludrocortisone (0.04 mg/kg). Results: Central activity and anxiety index were increased 1 h after exposure to FST, while an increase in the anxiety index was observed 24 h after exposure to FST in the open field test compared to the non-stressed mice. Corticosterone, dexamethasone, and fludrocortisonedecreased central activity and anxiety index 1 h after the administration, compared to the control group. However, fludrocortisone decreased central activity and total locomotor activity 24 h after administration compared to the control group. Conclusion: A similar pattern of enhancement of anxiety-like behavior was observed in mice 1 h after FST or the administration of corticosterone (single dose 20 mg/kg, i.p.), dexamethasone(single dose 10 mg/kg, i.p.), and fludrocortisone (single dose 0.04 mg/kg, i.p.). Nonetheless, 24 h after exposure to stress or administration of the studied substances, FST decreased ALB, fludrocortisone enhanced ALB, while corticosterone and dexamethasone showed no effect on ALB in mice 24 h after exposure to stress or administration of the studied substances.