Effects of nerve growth factor (NGF) in rats with basal forebrain lesions.

Effects of nerve growth factor (NGF) on the basal forebrain (BF) lesion-induced amnesia in rats were investigated. When NGF infusion was begun immediately after the formation of BF lesions, NGF ameliorated amnesia in a water maze task and showed a tendency to increase choline acetyltransferase (CAT) activity in the fronto-parietal cortex. The amnesia and the decrease of CAT activity were not ameliorated when NGF infusion was begun 4 weeks after BF lesion formation. These observations suggest that NGF may act as a trophic and/or a protective factor on partially damaged cholinergic neurons and that the efficacy of NGF was influenced by the phase of neuronal damage.