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 win-stay, radial arm maze task. Pretraining lesions on the former task did not affect foraging for 4 pellets during either the training or test phases. In contrast, lesions given prior to the test phase significantly disrupted retrieval of 4 pellets on the 8-arm maze. Comparable deficits also were observed in rats trained to forage for 4 pellets on an 8-arm maze without prior win-shift experience. State-dependent drug effects were ruled out by replicating the disruptive effects of lidocaine infusions into the N.Acc. on spatial win-shift performance in rats receiving this treatment prior to both training and test phases. These results suggest that the N.Acc. may interact with the hippocampus to guide foraging behavior requiring memory of previous spatial locations on a maze.