Enteric nervous system and colonic smooth muscle (ENS)

The enteric nervous system (ENS) is a vast, quasi-autonomous network of neurons and glial cells residing within the wall of the gastrointestinal tract, often termed the 'second brain' (StatPearls, NBK545275). It works in concert with the colonic smooth muscle to coordinate complex behaviors such as peristalsis, mass movements, and haustral churning (Frontiers in Physiology, 2012). The ENS regulates these movements by releasing excitatory neurotransmitters like acetylcholine or inhibitory transmitters like nitric oxide directly onto the smooth muscle cells (Journal of Clinical Investigation, 2003). This system is the primary site of pathology in disorders such as Hirschsprung's disease, where neurons are absent, and irritable bowel syndrome (IBS), where neuro-muscular signaling is dysregulated (Nature Reviews Gastroenterology & Hepatology, 2018). Therapeutic strategies targeting this system include 5-HT4 receptor agonists to stimulate motility and mu-opioid receptor antagonists to alleviate constipation (Pharmacological Reviews, 2017). Understanding the interaction between ENS signaling and smooth muscle contractility is crucial for developing prokinetic and antispasmodic drugs (Annual Review of Pharmacology and Toxicology, 2006).

Other names

ENSIntrinsic nervous systemGastrointestinal neuromuscular systemGut brain

Modulation of neurotransmitter receptors (e.g., 5-HT4, mu-opioid) and ion channels (e.g., ClC-2, GC-C) to alter neuronal firing and smooth muscle contractility.