Acetylcholine release during burst-patterned stimulation of a sympathetic ganglion: its relation to transmission efficiency.

The time-course of increase in acetylcholine (ACh) output during burst-patterned preganglionic stimulation of the cat superior cervical ganglion has been determined. The increase in output corresponded closely with the increase in transmission efficiency found earlier in the stellate ganglion subjected to similar preganglionic stimulation. ACh output however continued to increase following the time of attainment of full neuronal recruitment. The results indicate that the increase in ACh output may largely account for the increase in transmission; but they leave unexplained the synaptic function of the continuing increase in transmitter release.