The effect of Metformin on tactile learning and anxiety like-behavior in ovariectomized mice

Abstract

Introduction: Estrogen regulates many processes in the brain such as synaptic formation, learning, and memory. Empirical evidence shows that there is a correlation among menopause, memory impairment, and anxiety due to Estrogen deficiency. In this study, we tested the effect of Metformin (Met) with antioxidant effect, which can improve the impairment of tactile learning and anxiety-like behavior in ovarectomized mice. Methods: Thirty-two female mice weighting 20±5 g were randomly divided into four groups of eight, including sham group, ovariectomy, ovariectomy with doses 7 and 15 mg/kg of Met. At first, mice were ovariectomized and then they were treated with the doses of the Met or water for 21 days. Then, tactile learning (by Novel Object Recognition Test) and anxiety like-behavior (by Elevated Plus-maze) were determined. Results: Met at the doses of 7 or 15 mg/kg significantly improved tactile learning compared to the ovariectomy group. Met at the doses of 7 or 15 mg/kg significantly increased Open Arm Time (%OAT) and Open Arm Entries (%OAE) compared to the ovariectomy group. Conclusion: Met especially at the dose of 7 mg/kg showed a significant role in improving the anxiety and tactile learning in the ovariectomized mice.

Keywords

• Ovariectomy
• Metformin
• Learning
• Anxiety