Locus coeruleus lesions and avoidance behavior in rats

Bilateral electrolytic lesions of the locus coeruleus were performed in rats. In comparison with controls, lesioned rats showed decreased acquisition of two-way avoidance response, less intertrial responses, longer latency of avoidance responses on the first day of training, and needed more trials to reach the extinction criterion. It is suggested that locus coeruleus, contrary to the ventral noradrenergic bundle, facilitates avoidance behavior in rats.