Aging and neural control of the GI tract. I. Age-related changes in the enteric nervous system.

As we enter the 21st century, the segment of the population that is the most rapidly expanding is that comprised of individuals 85 yr of age and older. Dysfunctions of the gastrointestinal (GI) system, including dysphagia, constipation, diarrhea, and irritable bowel syndrome are more common complaints of the elderly, yet our knowledge of the aging GI tract is incomplete. Compared with the rapid advances in the neurobiology of aging in the central nervous system, the understanding of age-related changes in the enteric nervous system (ENS) is poor. In this brief review, I recap experiments that reveal neurodegenerative changes and their functional correlates in the ENS of mice, rats, and guinea pigs. Clinical literature seems indicative of similar structural and functional age-related changes in the human ENS. Current studies that address the mechanisms underlying age-related changes in the ENS are introduced. The future directions for this field include physiological and pharmacological studies, especially at cellular and molecular levels. Research in the aging ENS is poised to make major advances, and this new knowledge will be useful for clinicians seeking to better understand and treat GI dysfunction in the elderly.

[1]  T. Burks,et al.  Age-related changes in colonic function in rats. , 1984, The American journal of physiology.

[2]  E. Fehér,et al.  Density of substance P, vasoactive intestinal polypeptide and somatostatin-containing nerve fibers in the ageing small intestine of the rats. , 1987, Gerontology.

[3]  R. Santer,et al.  Enteric neuron numbers and sizes in Auerbach's plexus in the small and large intestine of adult and aged rats. , 1988, Journal of the autonomic nervous system.

[4]  D. Harman,et al.  Lipofuscin and ceroid formation: the cellular recycling system. , 1989, Advances in experimental medicine and biology.

[5]  G. Gabella,et al.  Fall in the number of myenteric neurons in aging guinea pigs. , 1989, Gastroenterology.

[6]  Caleb E. Finch,et al.  Longevity, senescence, and the genome , 1990 .

[7]  A R Zinsmeister,et al.  Prevalence of gastrointestinal symptoms in the elderly: a population-based study. , 1992, Gastroenterology.

[8]  J. Wiley,et al.  Evidence for age-associated reduction in acetylcholine release and smooth muscle response in the rat colon. , 1994, The American journal of physiology.

[9]  R. Santer.  Survival of the population of NADPH-diaphorase stained myenteric neurons in the small intestine of aged rats. , 1994, Journal of the autonomic nervous system.

[10]  L. Johnson,et al.  Physiology of the gastrointestinal tract , 2012 .

[11]  R. D. de Souza,et al.  Nerve cell loss in the myenteric plexus of the human esophagus in relation to age: a preliminary investigation. , 1995, Gerontology.

[12]  R. Lefebvre,et al.  Influence of aging on gastric emptying of liquids, small intestine transit, and fecal output in rats , 1996, Experimental Gerontology.

[13]  M. Hongo,et al.  Effect of aging on the esophageal motor functions. , 1996, Journal of smooth muscle research = Nihon Heikatsukin Gakkai kikanshi.

[14]  E. Liberti,et al.  A preliminary investigation of the effects of aging on the nerve cell number in the myenteric ganglia of the human colon. , 1997, Gerontology.

[15]  G. Vantrappen,et al.  The aging oesophagus , 1997, Gut.

[16]  E. Ferriolli,et al.  Aging, Esophageal Motility, and Gastroesophageal Reflux , 1998, Journal of the American Geriatrics Society.

[17]  T. Ishii,et al.  Decrease in participation of nitric oxide in nonadrenergic, noncholinergic relaxation of rat intestine with age. , 1998, Japanese journal of pharmacology.

[18]  P. Puri,et al.  Morphometric aspects of the submucous plexus in whole-mount preparations of normal human distal colon. , 1998, Journal of pediatric surgery.

[19]  K. Hall,et al.  Neural injury, repair and adaptation in the GI tract. I. New insights into neuronal injury: a cautionary tale. , 1998, The American journal of physiology.

[20]  O. Sandström,et al.  Age-induced changes in the enteric nervous system in the mouse , 1999, Mechanisms of Ageing and Development.

[21]  A. Gelb,et al.  Aging and gastrointestinal physiology. , 1999, Clinics in geriatric medicine.

[22]  A. Pilotto,et al.  Aging and the gastrointestinal tract. , 2003, Italian journal of gastroenterology and hepatology.

[23]  D. O’Briain,et al.  Notable postnatal alterations in the myenteric plexus of normal human bowel , 1999, Gut.

[24]  A. Powell,et al.  Differential effects of maturation on nicotinic- and muscarinic receptor-induced ion secretion in guinea pig distal colon. , 2000, Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine.

[25]  S. Rose,et al.  Functional bowel disorders in the geriatric patient: constipation, fecal impaction, and fecal incontinence , 2000, American Journal of Gastroenterology.

[26]  Toku Takahashi,et al.  Decreased expression of nitric oxide synthase in the colonic myenteric plexus of aged rats , 2000, Brain Research.

[27]  E. Tangalos,et al.  Insights into the Pathophysiology and Mechanisms of Constipation, Irritable Bowel Syndrome, and Diverticulosis in Older People , 2000, Journal of the American Geriatrics Society.

[28]  T. Cowen,et al.  Restricted diet rescues rat enteric motor neurones from age related cell death , 2000, Gut.

[29]  Richard Weindruch,et al.  Gene-expression profile of the ageing brain in mice , 2000, Nature Genetics.

[30]  T. Cowen,et al.  Free radical induced cell death in ageing rat enteric neurons: role of diet and neurotrophic factors , 2001 .

[31]  T. Powley,et al.  As the gut ages: Timetables for aging of innervation vary by organ in the Fischer 344 rat , 2001, The Journal of comparative neurology.

[32]  S J Brookes,et al.  Classes of enteric nerve cells in the guinea‐pig small intestine , 2001, The Anatomical record.

[33]  T. Cowen.  Selective vulnerability in adult and ageing mammalian neurons , 2002, Autonomic Neuroscience.

[34]  P. Rutgeerts,et al.  Budesonide in collagenous colitis: a double-blind placebo-controlled trial with histologic follow-up. , 2002, Gastroenterology.

[35]  R. Schmidt.  Age‐Related Sympathetic Ganglionic Neuropathology: Human Pathology And Animal Models , 2002 .

[36]  H. Hidaka,et al.  Neurocalcin-α immunoreactivity in the enteric nervous system of young and aged rats , 2002 .

[37]  G. Burnstock,et al.  Effect of age on NADPH-diaphorase-containing myenteric neurones of rat ileum and proximal colon , 1995, Cell and Tissue Research.