We report here the behavioral and biochemical recovery induced by the nerve growth factor (NGF) administration in AF64A-treated rats. Retention in the passive avoidance test was affected by lesion but it was significantly improved after the NGF treatment. Similar resultas were observed in the performance during the Morris water maze (MWM) task. Remarkable losses in the ChAT activity were detected in some brain regions from lesioned rats. The NGF-induced alleviation of choline acetyl transferase (ChAT) activity losses and cognitive functions suggest a trophic and protective action on the remaining cholinergic neurons after the lesion. Thus NGF therapy could be considered as a possibility mainly in the early course of Alzheimer disease