Experimental brain injury reduces the accuracy of spatial-delayed alternation performance

Memory dysfunction after traumatic brain injury is common when areas surrounding the hippocampus are damaged. In the present study, the effects of a mild to moderate lateral fluid precussion injury on spatial working memory are examined. A spatial-delayed alternation procedure was used to assess spatial memory retention in 14 Sprague-Dawley rats for two weeks following fluid precussion or sham injury. In this procedure, a correct response resulted in the delivery of a food pellet, the only source of food for the rats. It was observed that the sham-injured group showed less of a deficit following "injury" than did the fluid precussion group. In addition, it was also noted that the fluid precussion group showed significant weight loss 5 and 10 days post-injury, suggesting severe spatial working memory impairment. Although histological studies were not performed, it is believed that the dysfunction observed on the task was due to damage to the hippocampus and perihippocampal areas.