POTENTIATION OF DEVELOPING NEUROMUSCULAR SYNAPSES BY THE NEUROTROPHINS NT-3 AND BDNF

THE neurotrophins are a family of neurotrophic factors that promote su rvival and differentiation of various neuronal populations1,2. Althoug h the long-term effects of neurotrophins on neuronal survival and diff erentiation have been intensively studied, nothing is known about thei r effects on synaptic function. Here we report that acute exposure to neurotrophin-3 (NT-3)3,4 or brain-derived neurotrophic factor (BDNF)5, but not nerve growth factor (NGF)6, rapidly potentiates the spontaneo us and impulse-evoked synaptic activity of developing neuromuscular sy napses in culture. The effect appears to be presynaptic in origin and to be mediated by the Trk family of receptor tyrosine kinases7. These results provide evidence for the regulation of the function of develop ing synapses by neurotrophins.