Chronic restraint stress impairs acquisition and retention of spatial memory task in rats

Abstract

Chronic restraint stress causes dendritic atrophy of CA3 pyramidal neurons of the hippocampus. In this study, we assessed the functional consequences of dendritic atrophy on the acquisition and retention of spatial memory, using a T-maze task. 45-day-old male Wistar rats, subjected to 6 h of daily restraint stress over a period of 21 days, were tested for left-right discrimination task for food reward in a T-maze. We found a significant (P < 0.001) deficit in both acquisition and retention of the task in stressed rats compared to controls. To rule out the possibility that gastric ulcers, induced by stress, could work as a deterrent for rats to seek the food reward, rats were also treated with an antacid. Even though the antacid treatment prevented the stress-induced ulcer formation, the learning and memory deficits were not prevented. These results demonstrate that chronic restraint stress impairs spatial learning and memory in rats.