You know that feeling you get when you have a hunch, an intuition, or a “gut” sense about something? It’s long been referred to as intuition (or inexplicable ways we can sense risk and danger), but there may be something about why we call it a “gut” sense after all.
Researchers from the University of Illinois have uncovered a complex network inside the gut which influences more than just basic biological functions; they are signaling the higher brain and emotional centers. We’ve known about the connection between the gut bacteria and the brain, called the gut-brain axis, but this new research connects the gut straight to the neurons of the brain itself.
The neurons were found to do two types of signaling: motor and sensory. This type of double-duty had only ever been noted in connections between fat tissue and the brain. Previously, scientists believed that sensations from the body (including the gut) sent signals along the sensory neurons to the brain, and any further communication from the brain went separately through motor neurons. However, half the neurons that they discovered in the gut were actually capable of sending signals directly to the brain and capable of receiving communication directly back to the original sender.
This feedback loop was noted across all the areas in the brain. It offers an explanation for how information from nutrients and bacteria reach the brain, and why the environment of the gut influences emotional processes. An abundance of harmful bacteria can alter emotional and mental states and has been found in some psychological diseases, but it wasn’t clear how the brain could be aware of the subtleties occurring in the gut (like when you are irritable when very hungry). Also, it wasn’t clearly understood how the state of the brain could influence the gut; such as when you’re having a stressful day, and the gut reacts with cramping, stomach upset, and diarrhea.
Scientists believe that the secret of intuition may also lie at the connection between the gut and the brain and how they influence one another. With time, this network may explain why sometimes when we receive a shock or extreme emotional news, we feel like we were “kicked in the stomach.”
Coltan G. Parker, Megan J. Dailey, Heidi Phillips, Elizabeth A. Davis. Central sensory-motor crosstalk in the neural gut-brain axis. Autonomic Neuroscience, 2020; 225: 102656 DOI: 10.1016/j.autneu.2020.102656