Disturbance of brightness discrimination and active avoidance learning after lesions of nucleus reticularis tegmenti pontis (NRTP) of rats are related to impairment of goal-directed behaviour.

Long-Evans hooded rats were not able neither to reach criterion of active avoidance tasks in a Y-maze and in a jump test, nor in brightness discrimination after lesions of the NRTP without preoperative experience in these tests. After preoperative consolidation of active avoidance, the retention of Y-maze avoidance performance was zero and of jump test avoidance at 25%. The Y-maze avoidance was again relearned except in the task with 2:2 alternation of goals whereas retention of brightness discrimination was not affected. In the jump test, avoidance relearning was evidently retarded. Ambulatory and exploratory behaviour in the open field were significantly reduced after NRTP lesions. The NRTP is evidently involved in the establishment and control of goal-directed behaviour.