Figure 2.
Autonomic nervous and microbial-derived neurotransmitters regulate gut barrier integrity. A number of checks and balances operate to sense and manage luminal danger signals. Details are discussed throughout the article. Abbreviations: 5-HT, serotonin; ACh, acetylcholine; CRF, corticotrophin releasing factor; EGF, epidermal growth factor; GDNF, glial cell line-derived neurotrophic factor; LPS, lipopolysaccharide; M3, M3 muscarinic receptor; SCFA, short chain fatty acids; sIgA, secretory IgA; SNO, s-nitrosothiol; TGF, transforming growth factor; TJ, tight junction; VIP, vasoactive intestinal peptide; VPAC1, VIP and pituitary adenylate cyclase-activating peptide receptor 1.