THE EFFECTS OF CHRONIC CORTICOSTERONE ON MEMORY PERFORMANCE IN THE PLATFORM MAZE TASK

Acquisition and reversal of a memory task dependent on hippocampal int egrity were assessed in rats following chronic corticosterone treatmen t. Young adult male rats were injected daily with corticosterone (10 m g/kg, SC) for 8 weeks. Memory was assessed during the last week of tre atment with an elevated platform maze. During acquisition trials, cort icosterone-treated rats did not differ from vehicle-treated controls i n either the location of first hole chosen nor in the latency to locat e the escape hole. In the reversal trials, when the position of the es cape hole was rotated 135 degrees, both groups successfully reversed t heir responses without persevering towards the previously rewarded esc ape hole location. These findings suggest that, despite the probabilit y of corticosterone-induced changes in hippocampal physiology, chronic corticosterone treatment does not adversely affect performance in a m emory task dependent on hippocampal integrity.