Nerve growth factor binding in aged rat central nervous system: effect of acetyl-L-carnitine

The nerve growth factor protein (NGF) has been demonstrated to affect neuronal development and maintenance of the differentiated state in certain neurons of the peripheral and central nervous system (CNS) of mammals. In the CNS, NGF has sparing effects on cholinergic neurons of the rodent basal forebrain (BF) following lesions where it selectively induces choline acetyltransferase (ChAT). NGF also induces ChAT in the areas to which BF provides afferents. In aged rats, there is a reduction in the NGF-binding capacity of sympathetic ganglia. Here, we wish to report that there is a decrease in the NGF-binding capacity of the hippocampus and basal forebrain of aged (26-month-old) rats as compared to 4-month-old controls but no change in NGF binding in cerebellum. In all instances, equilibrium binding dissociation constants did not differ significantly. Treatment of rats with acetyl-L-carnitine, reported to improve cognitive performance of aged rats, ameliorates these age-related deficits.