ACIDIC FGF INDUCES NGF AND ITS MESSENGER-RNA IN THE INJURED NEOCORTEXOF ADULT ANIMALS

Recently we reported that human recombinant acidic fibroblast growth f actor (aFGF) is capable of preventing degeneration of nucleus basalis magnocellularis neurons in vivo and inducing growth of astrocytes in v itro. In the present study, the effects of aFGF on the concentration o f nerve growth factor (NGF) and its messenger RNA were investigated in the rat cerebral cortex following unilateral cortical infarction. Les ioned animals exhibited a significant increase of NGF in the remaining cortex ipsilateral to the lesion. After combining cortical lesion wit h intracerebroventricular application of aFGF (12 mu g/day for 7 days) , we observed an 8-fold increase in the NGF concentration and a marked increase in the level of steady state NGF mRNA relative to controls i psilaterally, and a less pronounced aFGF effect in the contralateral c erebral cortex. These results support the hypothesis that the neurotro phic effects previously shown for aFGF and basic FGF (bFGF) in neurotr ophin-sensitive neurons is mediated by inducing increased production o f NGF within the injured central nervous system (CNS) of adult animals .