The FASEB Journal, Vol 3, 127-138, Copyright © 1989 by The Federation of American Societies for Experimental Biology

REVIEWS

Role of the "little brain" in the gut in water and electrolyte homeostasis

HJ Cooke
Department of Physiology, Ohio State University, Columbus 43210.

The enteric nervous system plays a key role in maintenance of body fluid homeostasis by regulating the transport of ions by the intestinal epithelium. The epithelial cells normally absorb large volumes of fluid and ions daily, but tonically active submucosal neurons continuously suppress ion transport and limit the absorptive capacity of the intestine. Specialized nerve endings detect chemical, osmotic, or thermal alterations of the luminal contents or mechanical activity of the gut wall and encode this information as action potentials that propagate along nerve processes to the ganglia. Information transfer within the ganglia occurs at nicotinic cholinergic or other synapses. Ion transport is altered when neurotransmitters released from motor neurons interact with receptors on epithelial cells to initiate stimulus-response coupling. The signals that transduce changes in epithelial ion transport are largely unknown, except for acetylcholine, but may include vasoactive intestinal peptide or other peptides. These trigger changes in intracellular messengers that influence the state of ionic channels in the epithelial cells and thereby inhibit absorptive processes or stimulate secretory mechanisms. When conservation of salt and water is necessary, command signals from the central nervous system, and perhaps from the myenteric ganglia, will shut down the synaptic circuits in the submucosal ganglia and enhance the absorptive capacity of the bowel.

This article has been cited by other articles:

				J. A. Armour Potential clinical relevance of the 'little brain' on the mammalian heart Exp Physiol, February 1, 2008; 93(2): 165 - 176. [Abstract] [Full Text] [PDF]

				Subcommittee on Chronic Abdominal Pain Chronic Abdominal Pain in Children Pediatrics, March 1, 2005; 115(3): 812 - 815. [Abstract] [Full Text] [PDF]

				W. K. MacNaughton, M. D. Van Sickle, C. M. Keenan, K. Cushing, K. Mackie, and K. A. Sharkey Distribution and function of the cannabinoid-1 receptor in the modulation of ion transport in the guinea pig ileum: relationship to capsaicin-sensitive nerves Am J Physiol Gastrointest Liver Physiol, May 1, 2004; 286(5): G863 - G871. [Abstract] [Full Text] [PDF]

				A. Chalazonitis, T. D. Pham, T. P. Rothman, P. S. DiStefano, M. Bothwell, J. Blair-Flynn, L. Tessarollo, and M. D. Gershon Neurotrophin-3 Is Required for the Survival-Differentiation of Subsets of Developing Enteric Neurons J. Neurosci., August 1, 2001; 21(15): 5620 - 5636. [Abstract] [Full Text] [PDF]

				H. Pan and M. D. Gershon Activation of Intrinsic Afferent Pathways in Submucosal Ganglia of the Guinea Pig Small Intestine J. Neurosci., May 1, 2000; 20(9): 3295 - 3309. [Abstract] [Full Text] [PDF]