Intrahippocampal Injection of 3α Diol (a Testosterone Metabolite ) and Indomethacin (3α-HSD Blocker), Impair Acquisition of Spatial Learning and Memory in Adult Male Rats

Abstract

Hippocampus is essentially involved in learning and memory processes, and is known to be a target for androgen actions. The high density of the androgen receptors in hippocampus shows that there must be some relationship between androgens and memory. Androgen effects on spatial memory are complex and contradictory. Some evidence suggests a positive correlation between androgens and spatial memory. While some other reports indicated an impairment effect. The present study was conducted to assess the effect of 3α diol on spatial discrimination of rats. Adult male rats were bilaterally cannulated into CA1 region of hippocampus and then received 3α diol (0.2, 1, 3 and 6 μg/ 0.5 μL/side), indomethacin (1.5, 3 and 6 μg/ 0.5 μL/side), indomethacin (3 μg/ 0.5 μL/side) + 3α diol (1μg/ 0.5 μL/side), 25-35 min before training in Morris Water Maze task. Our results showed that injection of 3α diol (1, 3 and 6 μg/ 0.5 μL/side) and indomethacin (3 and 6 μg/ 0.5 μL/side) significantly increased the escape latency and traveled distance to find hidden platform. It is concluded that intra CA1 administration of 3α diol and indomethacin could impair spatial learning and memory in acquisition stage. However, intra hippocampal injection of indomethacin plus 3α diol could not change spatial learning and memory impairment effect of indomethacin or 3α diol in Morris Water Maze task.