The study of spatial memory in adult male rats with injection of testosterone enanthate and flutamide into the basolateral nucleus of the amygdala in Morris water maze

Abstract

Extensive evidence suggests that the amygdala is involved in memory. The presence of androgenic and estrogenic receptors in the amygdala may reflect a possible involvement in certain activities of this part of the brain. Since sex steroids are known to play role in the maintenance and modulation of behavior, particularly spatial cognition throughout the life span, it was interesting to explore the role of these receptors in spatial memory. Therefore, an experiment was designed to investigate the effect of testosterone enanthate as an agonist and flutamide as an antagonist of androgenic receptors on spatial memory and learning. Wistar rats were bilaterally cannulated into basolateral nucleus of amygdala. Animals in different groups including vehicle (dimethyl sulfoxide) were proven to be inert for memory and learning. Testosterone enanthate (20, 40, 80 and 120 μg/0.5 μl), and flutamide (2, 5, 10, 20 and 40 μg/0.5 μl) were injected in both cannulae 30 min before each training day. After 4 days of experiments, results indicate a dose-dependent increase in parameters of escape latencies and travel distances to find the invisible platform in the group that received 120 μg/0.5 μl testosterone enanthate as compared to the control and vehicle groups. Flutamide had no effect on spatial memory. Therefore, it appears that androgens may effect memory and learning in amygdala. This is a feature that requires further investigation.