Gut neurons may offer way to treat constipation in Parkinson’s: Study

Stanford University researchers have identified a type of nerve cell in the gut that plays a key role in regulating bowel movements. These neurons, which release the signaling molecule glutamate, are part of the enteric nervous system—a network of nerve cells embedded in the gut wall. Their discovery, based on studies in mice, could lead to new treatments for constipation in Parkinson’s disease. The research team found that glutamatergic interneurons, which connect other nerve cells, help control intestinal motility—the muscle movements that push food and waste through the digestive system. Further studies are needed to better understand how these neurons process information within the enteric nervous system. Led by Julia Kaltschmidt, PhD, the study explored how the gut’s nervous system influences digestion and overall health. The team identified two types of glutamatergic neurons in the mouse gut, both expressing a protein called VGLUT2, which regulates glutamate storage and release. One type extended along the small intestine and colon, while the other formed circular networks in the colon. These neurons not only used glutamate but also other neurotransmitters like acetylcholine and enkephalin to coordinate gut muscle movement. When researchers removed VGLUT2 from some neurons, the mice processed food much faster and produced more but smaller fecal pellets. Stimulating these neurons in a lab setting prompted the colon to push food forward, confirming their role in controlling bowel movements. Kaltschmidt’s team is now exploring the development of a "gut pacemaker" to help regulate bowel movements, which could benefit people with Parkinson’s and those experiencing age-related constipation. She emphasized that digestion is fundamental to movement and cognition, highlighting the growing recognition of the enteric nervous system’s broader importance.