POTENTIATION OF TRANSMITTER RELEASE BY CILIARY NEUROTROPHIC FACTOR REQUIRES SOMATIC SIGNALING

Neurotrophic factors participate in the development and maintenance of the nervous system. Application of ciliary neurotrophic factor (CNTF) , a protein that promotes survival of motor neurons, resulted in an im mediate potentiation of spontaneous and impulse-evoked transmitter rel ease at developing neuromuscular synapses in Xenopus cell cultures. Wh en CNTF was applied al the synapse, the onset of the potentiation was slower than that produced by application at the cell body of the presy naptic neuron. The potentiation effect was abolished when-the neurite shaft was severed from the cell body. Thus, transmitter secretion from the nerve terminals is under immediate somatic control and can be reg ulated by CNTF.