Presynaptic regulation of the release of acetylcholine by 5-hydroxytryptamine.
1 The effect of 5-hydroxytryptamine (5-HT) on the release of acetylcholine (ACh) from bullfrog sympathetic preganglionic nerve terminals and frog sciatic nerve terminals was studied with intra-cellular microelectrodes. 2 The change in transmitter release was measured from the mean quantal content calculated by the variance method from evoked fast e.p.s.ps or e.p.ps in low Ca2+-high Mg2+ Ringer solution. 3 5-HT facilitated the release of ACh in low concentrations and depressed it in relatively high concentrations at both preganglionic and motor nerve terminals. 4 These results suggest the possibility that 5-HT may play a role in regulating cholinergic transmission in general.
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D066298:In Vitro Techniques; D009046:Motor Neurons / Q000378:metabolism; D009411:Nerve Endings / Q000378:metabolism; D011892:Rana catesbeiana; D011898:Ranidae; D012701:Serotonin / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D013997:Time Factors
D012701:Serotonin; D000109:Acetylcholine