Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9186586 | Autonomic Neuroscience | 2005 | 5 Pages |
Abstract
Motilin is considered as a key factor in controlling interdigestive migrating contractions. The present electrophysiological experiments were performed in vitro to examine actions of motilin on myenteric neurons of guinea-pigs after 18-h fasting period. Superfusion of motilin depolarized both S and AH neurons; the lowest effective concentration was 10 nM, and motilin depolarization was observed in 9 of 23 S neurons and in 5 of 25 AH neurons. The motilin depolarizations were associated with an increase in neuronal input resistance. The motilin responses were preserved in Ca2+ free/high Mg2+ solution in which no Ca2+ dependent synaptic transmission occurred. The reversal potential of the motilin responses was estimated about â95 mV, close to the equilibrium potential for K+. Furthermore, muscarinic depolarizations were blocked during the motilin responses. All of these indicated that motilin directly excited myenteric neurons mainly by inactivating K+ channels. It is concluded that motilin might modulate neuronal excitability of the myenteric plexus, leading to the control of interdigestive migrating contractions.
Related Topics
Life Sciences
Neuroscience
Cellular and Molecular Neuroscience
Authors
Yoshifumi Katayama, Kiyotoshi Ooishi, Keiji Hirai, Tomoo Homma, Yumi Noda,