BrainDerivedGrowthFactor(BDNF) promotesthesurvivalofneuronalpopulationsthatarealllocatedeitherinthecentralnervoussystemordirectlyconnectedtoit.Majorregulatorofsynaptictransmissionandplasticityatadultsynapsesinmanyregionsofthecns.theversatilityof BDNFisemphasizedbyitscontributiontoarangeofadaptiveneuronalresponsesincludinglong-termpotentiation(ltp),long-termdepression(ltd),certainformsofshort-termsynapticplasticity,aswellashomeostaticregulationofintrinsicneuronalexcitABIlity.