Actually, it's about 50-50, unless you consider the stomach, esophagus, and large intestine as your "gut" — then there are more in your gut. The gut and the brain have about a hundred million neurotransmitters each. This isn't surprising if you consider that the gut and brain develop in an embryo from the same piece of tissue. The tissue eventually divides during development, one part going to the brain, the other to the gut. Many scientists think of the gut as the second brain.
More Gut-wrenching Facts:
- The gut and the brain are tied together directly by the vagus nerve, which starts in the brain, goes down through the neck and connects in the abdomen.
- The gut and the brain are so closely tied that they both have 90-minute sleep cycles.
- More serotonin is produced in the gut than anywhere else in the body, approximately 95 percent. It also produces benzodiazepines, the chemicals that are used to develop anti-anxiety drugs. When a person is injured, the gut sends benzodiazepine to the brain, relieving pain or even causing unconsciousness.
- Your gut has so many of its own nerve cells that it can still function even if it's separated from the spinal cord.