Neuro-immune interactions in intestinal inflammation

Clinical observations support the notion that there is neuro-modulation of the intestinal inflammation and that, conversely, inflammation alters neurally-mediated intestinal physiology. This concept of a bi-directional interaction is supported by work in animal models of intestinal inflammation. It has long been shown that inflammation alters enteric, autonomic and central nervous system functions in these models. It is also becoming increasingly evident that manipulation of these nervous systems will modulate the intestinal inflammatory response. In addition to increasing our understanding of neuro-immune interactions, these findings also offer the opportunity of novel therapeutic approaches to treating inflammatory bowel disease (IBD). Of recent interest in this regard are the roles of autonomic and sensory neurotransmitters. The clinical impression that nicotine or clonidine influence IBD has stimulated interest in the therapeutic potential of autonomic modulation in the treatment of IBD. Similarly, the apparent benefit of local anaesthetics in distal colitis has raised in the therapeutic value of manipulating substance P and calcitonin gene-related peptide for therapeutic gain in IBD.