The basal forebrain cholinergic system and object memory in the rat.

Rats with near complete destruction of basal forebrain cholinergic neurons from intracerebroventricular injections of 192 IgG-saporin were trained on object discrimination problems and then retrained two weeks later to measure retention. Despite dramatic reductions of acetylcholinesterase-positive fibers in hippocampus and neocortex, these animals did not differ from controls on an analysis of savings scores. Thus, the basal forebrain cholinergic system may serve functions that support non-spatial memory but are not specifically mnemonic in nature.