Spatial and non-spatial learning in the rat following lesions to the nucleus locus coeruleus

The present experiment examined the effects of unilateral or bilateral locus coeruleus lesions on general activity, acquisition of a non-monotonic serial pattern (14-0-3-7 food pellets, respectively), and response learning acquisition in a Greek cross version of the Morris water maze. Sham-operated control rats were capable of tracking the elements of the serial pattern while rats with a unilateral locus coeruleus lesion were moderately impaired, and those with bilateral locus coeruleus lesions were severely impaired. A similar pattern of working memory deficits emerged in an analysis of the response-learning data in the Greek cross. The results are discussed in terms of the current understanding of norepinephrine and the locus coeruleus in learning and memory processes.