ANTIBODIES TO NERVE GROWTH-FACTOR (NGF) PROLONG THE SENSITIVE PERIOD FOR MONOCULAR DEPRIVATION IN THE RAT

NEURAL plasticity in the visual cortex, as tested by changes in its fu nctional organization induced by monocular deprivation (MD), is presen t only during a restricted period of postnatal development (critical p eriod). To investigate whether this process of synapse strengthening d epends upon NGF, we antagonized endogenous NGF during the critical per iod by implanting anti-NGF producing cells. Anti-NGF treated and contr ol rats were monocularly deprived after the end of the critical period . In anti-NGF treated but not in control rats MD was still effective. We conclude that antagonism of endogenous NGF prolongs the critical pe riod, possibly by delaying the process of synapse consolidation in the visual cortex.