Abstract
It has been well established that glucocorticoid plays a key role in the formation of hippocampal dependent spatial memory in rodents. However, behavioral studies on the effect of only glucocoricoid (without other adrenal steroid hormones) on the animal,s spatial cognitive function have been few reported. Here, we investigated whether the chronically administration of corticosterone (25μg/ml) dissolved in daily drinking fluid (CORT) affects the spatial learning and memory in adrenalectomized (ADX) rats. Male Sprague-Dawley rats were divided into three groups (ADX, ADX+CORT and sham-ADX) and assigned to two water maze tasks to assess the abilities of rat,s spatial learning and memory retrieval. Escape latency, the time that animals locate the submerged platform under water surface, declined across every trial. Two-way analysis of variance (ANOVA) for rat,s learning performance revealed no differences between all groups. In memory retrieval test, they searched in target quadrant longer than others. Fischer,s PLSD test showed that ADX+CORT group significantly remembered platform location compared to ADX group. These data suggest that rats with ADX could also learn and retrieve similar to sham-ADX group, single administration of corticosterone to ADX rats reinforces spatial memory retrieval. [J Physiol Sci. 2007;57 Suppl:S134]
