SELECTIVE MEMORY IMPAIRMENTS PRODUCED BY TRANSIENT LIDOCAINE-INDUCED LESIONS OF THE NUCLEUS-ACCUMBENS IN RATS

Reversible lidocaine-induced lesions of the nucleus accumbens (N.Acc.) impaired performance on the spatial win-shift, but not on the cued wi n-stay, radial arm maze task. Pretraining lesions on the former task d id not affect foraging for 4 pellets during either the training or tes t phases. In contrast, lesions given prior to the test phase significa ntly disrupted retrieval of 4 pellets on the 8-arm maze. Comparable de ficits also were observed in rats trained to forage for 4 pellets on a n 8-arm maze without prior win-shift experience. State-dependent drug effects were ruled out by replicating the disruptive effects of lidoca ine infusions into the N.Acc. on spatial win-shift performance in rats receiving this treatment prior to both training and test phases. Thes e results suggest that the N.Acc. may interact with the hippocampus to guide foraging behavior requiring memory of previous spatial location s on a maze.