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Gastrointestinal Motility Monitor (GIMM)
Published on: December 1, 2010
Modulation of submucosal cholinergic neurons by 5-hydroxytryptamine and neuropeptides
W M Yau1, J A Dorsett, M L Youther
1Department of Physiology, School of Medicine, Southern Illinois University, Carbondale 62901-6512.
The American Journal of Physiology
|December 1, 1990
Summary
This study investigated acetylcholine release in guinea pig small intestine submucous plexus. Serotonin stimulated release, modulated by neuropeptides, revealing distinct cholinergic neuron characteristics compared to the myenteric plexus.
Area of Science:
- Neuroscience
- Gastroenterology
- Pharmacology
Background:
- The submucous plexus, a key component of the enteric nervous system, regulates intestinal functions.
- Cholinergic neurons play a crucial role in gastrointestinal motility and secretion.
- Understanding the regulation of acetylcholine release is vital for comprehending gut physiology.
Purpose of the Study:
- To characterize the release of acetylcholine ([3H]ACh) from guinea pig small intestine submucous plexus.
- To investigate the modulatory effects of serotonin and various neuropeptides on ACh release.
- To compare the functional properties of submucosal cholinergic neurons with those of the myenteric plexus.
Main Methods:
- In vitro electrophysiological recordings from guinea pig small intestine submucous plexus.
- Field stimulation to evoke [3H]acetylcholine release.
- Dose-response studies with serotonin (5-HT) and neuropeptides.
- Pharmacological blockade using tetrodotoxin and calcium-free buffer.
Main Results:
- Stimulation evoked frequency-dependent ACh release, blocked by tetrodotoxin and calcium deprivation.
- Serotonin dose-dependently stimulated ACh release (ED50 = 5 x 10(-7) M).
- Dynorphin A inhibited 5-HT-evoked release, while somatostatin and galanin showed concentration-dependent modulatory effects (inhibition/excitation).
Conclusions:
- Submucous plexus cholinergic neurons exhibit distinct response characteristics compared to myenteric plexus neurons.
- Serotonin is a potent stimulator of ACh release in the submucosa.
- Neuropeptides differentially modulate cholinergic neurotransmission, offering targets for therapeutic interventions in gut disorders.
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