Nerve Growth Factor Content of Rat Brain Increases Following Basal-Forebrain Lesions Induced by Ibotenic Acid but Not by Electrolysis

We attempted to measure the change in the nerve growth factor (NGF) content in the hippocampus and parietal cortex following basal-forebrain lesions induced by ibotenic acid and electrolysis. The NGF content of the parietal cortex and hippocampus increased transiently on days 3 to 7, and then returned to the control level on day 14 after the lesion of the basal forebrain induced by ibotenic acid. Ibotenic acid decreased both the choline acetyltransferase (ChAT) activity in the parietal cortex and the dopamine content in the striatum. Electrolytic lesions of the basal forebrain decreased the dopamine content in the striatum, but did not affect the NGF content and ChAT activity in any of the brain regions examined. These results suggest that the mechanism of NGF synthesis is related to cholinergic, but not to dopaminergic, neurons in the basal forebrain.