MONOCLONAL-ANTIBODIES TO NERVE GROWTH-FACTOR AFFECT THE POSTNATAL-DEVELOPMENT OF THE VISUAL-SYSTEM

Exogenous supply of nerve growth factor (NGF) prevents the effects of monocular deprivation. This suggests that visual afferents may be comp eting for an endogenous neurotrophic factor, related to NGF, whose pro duction by postsynaptic cells depends on the activity of afferent fibe rs. To test the hypothesis that endogenous NGF may play a role in the functional and anatomical development of the rat geniculo cortical sys tem, the physiological action of NGF in the rat visual system was anta gonized by using two independent monoclonal antibodies which neutraliz e NGF (alpha D11 and 4C8). To provide a continuous supply of antibodie s during the period of visual cortical plasticity, alpha D11 or 4C8 an tibody-producing hybridoma cells were implanted in the lateral ventric le of rats at postnatal day 15. This resulted in dramatic alterations of two of the most important parameters characterizing the functional development of the visual system, namely, visual acuity and binoculari ty of cortical neurons and in shrinkage of cells in the lateral genicu late nucleus. This demonstrates that the action of endogenous NGF is n ecessary for the normal functional and anatomical development of the g eniculocortical system.