Effects of NBm lesions on T-maze performance and thalamic biochemistry

Fisher 344 rats underwent bilateral nucleus basalis magnocellularis (NBm) lesioning followed by testing in a delayed nonmatching-to-sample T-maze task. Both lesion and control animals acquired the task although the NBm animals were mildly impaired on acquisition and on trials to criterion. Increasing the delay reduced accuracy of performance equally in both groups. The NBm lesion did not alter the level of several thalamic amino acids. These data indicate that NBm lesioning does not produce a significant impairment in working or reference memory in this task and supports the hypothesis that NBm lesioning impairs attention.