AJP - Gastrointestinal and Liver Physiology, Vol 263, Issue 6 838-G846, Copyright © 1992 by American Physiological Society

ARTICLES

Actions of 5-hydroxytryptamine on myenteric neurons in guinea pig gastric antrum

J. F. Tack, J. Janssens, G. Vantrappen and J. D. Wood
Department of Physiology, College of Medicine, Ohio State University, Columbus 43210.

Intracellular recording methods were used to study the actions of 5-hydroxytryptamine (5-HT) on 257 myenteric neurons in the guinea pig gastric antrum. Application of 5-HT caused three types of postsynaptic responses. A fast-activating depolarizing response was accompanied by a decreased input resistance and desensitized quickly to repeated applications. It was mediated by a 5-HT3 receptor. A slowly activating depolarization, accompanied by an increase in the input resistance and enhancement of the excitability, was mainly observed in after hyperpolarizing/type 2 neurons. It was suppressed by the prokinetic benzamide compound renzapride, while classical 5-HT1-4 receptor antagonists had no effect, suggesting the involvement of a 5-HT1p receptor as described in small intestinal neurons. A long-lasting hyperpolarizing response, accompanied by a decreased input resistance, was observed in a small subset of neurons. This response seemed to be mediated by a 5-HT1a receptor. Superfusion of 5-HT caused a dose-dependent inhibition of the stimulus-evoked nicotinic cholinergic fast excitatory postsynaptic potential (EPSP), which was mediated by a presynaptic 5-HT1a receptor. 5-HT also presynaptically inhibited the slow EPSP.

This article has been cited by other articles:

				G. Sarnelli, P. V. Berghe, P. Raeymaekers, J. Janssens, and J. Tack Inhibitory effects of galanin on evoked [Ca2+]i responses in cultured myenteric neurons Am J Physiol Gastrointest Liver Physiol, June 1, 2004; 286(6): G1009 - G1014. [Abstract] [Full Text] [PDF]

				J Tack and G Sarnelli Serotonergic modulation of visceral sensation: upper gastrointestinal tract Gut, July 1, 2002; 51(90001): i77 - 80. [Abstract] [Full Text]

				P. Vanden Berghe, J. Tack, A. Andrioli, L. Missiaen, and J. Janssens Receptor-induced Ca2+ signaling in cultured myenteric neurons Am J Physiol Gastrointest Liver Physiol, June 1, 2000; 278(6): G905 - G914. [Abstract] [Full Text] [PDF]

				J Tack, B Coulie, A Wilmer, A Andrioli, and J Janssens Influence of sumatriptan on gastric fundus tone and on the perception of gastric distension in man Gut, April 1, 2000; 46(4): 468 - 473. [Abstract] [Full Text] [PDF]

				B. Coulie, J. Tack, D. Sifrim, A. Andrioli, and J. Janssens Role of nitric oxide in fasting gastric fundus tone and in 5-HT1 receptor-mediated relaxation of gastric fundus Am J Physiol Gastrointest Liver Physiol, February 1, 1999; 276(2): G373 - G377. [Abstract] [Full Text] [PDF]

				J Tack, B Coulie, A Wilmer, T Peeters, and J Janssens Actions of the 5-hydroxytryptamine 1 receptor agonist sumatriptan on interdigestive gastrointestinal motility in man Gut, January 1, 1998; 42(1): 36 - 41. [Abstract] [Full Text] [PDF]