Fig. 1.

Stress-induced alterations in gastrointestinal functions. Central stressors induce release of CRF, ACTH, and glucocorticoids, which have antiinflammatory actions. Centrally released CRF and Ucns activate parasympathetic nerves, which in turn innervates enteric neurons within the gut wall to stimulate or inhibit motility (depending on the region) and stimulate secretion. Peripheral stressors induce local release of CRF and Ucns, possibly from enteric neurons and immune cells. Peripherally derived CRF may act on enteric nerves, mast cells, and enterocytes to induce inflammation and control motility and secretion.