The effects of chronic corticosterone on memory performance in the platform maze task.

Acquisition and reversal of a memory task dependent on hippocampal integrity were assessed in rats following chronic corticosterone treatment. Young adult male rats were injected daily with corticosterone (10 mg/kg, SC) for 8 weeks. Memory was assessed during the last week of treatment with an elevated platform maze. During acquisition trials, corticosterone-treated rats did not differ from vehicle-treated controls in either the location of first hole chosen nor in the latency to locate the escape hole. In the reversal trials, when the position of the escape hole was rotated 135 degrees, both groups successfully reversed their responses without persevering towards the previously rewarded escape hole location. These findings suggest that, despite the probability of corticosterone-induced changes in hippocampal physiology, chronic corticosterone treatment does not adversely affect performance in a memory task dependent on hippocampal integrity.