Emerging pharmacology of nerve growth factor.

1. Partial transection of the septo-hippocampal pathway decreased measures of presynaptic cholinergic function in the rat hippocampal formation. 2. Chronic intraventricular treatment with recombinant human nerve growth factor attenuated lesioned-induced deficits in cholinergic function. Following nerve growth factor treatment measures of choline acetyltransferase activity, acetylcholine synthesis and release were significantly increased compared to cytochrome c-treated lesioned animals. 3. Single injections of nerve growth factor were ineffective in altering lesioned-induced deficits in cholinergic function. 4. Chronic nerve growth factor treatment was ineffective in increasing presynaptic cholinergic function if administered 3 or more weeks following fimbrial transections. 5. The nerve growth factor-induced increases of presynaptic cholinergic function persisted for 3 weeks following the cessation of chronic 3 week nerve growth factor treatment.