CHRONIC NICOTINE REVERSES WORKING-MEMORY DEFICITS CAUSED BY LESIONS OF THE FIMBRIA OR MEDIAL BASALOCORTICAL PROJECTION

Nicotine has been found in a variety of studies to improve performance in memory tasks. This study was conducted to determine if chronic nic otine administration is useful in counteracting the working memory def icits seen after lesions of the fimbria or the medial basalocortical p rojection. Rats were trained to asymptotic performance on a working me mory version of the radial-arm maze. Then, they were given knife cut l esions of the fimbria or the medial basalocortical projection or under went sham surgeries. At the time of surgery, rats in each treatment gr oup were implanted with either nicotine-containing or placebo glass an d Silastic pellets. Rats with fimbria or basalocortical lesions showed a significant decline in working memory performance. Chronic nicotine significantly improved choice accuracy in both lesioned and unlesione d rats. Nicotine treatment restored performance of the lesioned rats t o control levels. These data show that in addition to improving memory performance in normal rats, nicotine can counteract lesion-induced me mory impairments. Nicotine also may be useful for treatment of disease -related memory impairments such as seen in Alzheimer's disease.