The digestive system is endowed with its own, local nervous system referred to as the enteric or intrinsic nervous system. The magnitude and complexity of the enteric nervous system is immense – it contains as many neurons as the spinal cord.
Conventional medical treatment for neurological disorders such as epilepsy, migraine, and autism focuses on the brain. Although standard medical treatment is often helpful, the underlying causes of these disorders are not well understood. Furthermore, some individuals respond poorly, or not all to regular medicine. Evidence is accumulating in the medical literature that the enteric nervous system (ENS) – that part of the nervous system associated with the alimentary canal – also plays a role in these disorders. Historically, the concept of an autonomous abdominal nervous system was advocated by Byron Robinson, Johannis Langley, and Edgar Cayce. The work of these three prominent historical figures is considered along with modern viewpoints on the abdominal nervous system. Complementary therapies that address the nervous system of the abdomen hold potential as useful adjuncts to conventional treatment for certain neurological disorders.
As light is shed on the circuitry between the two brains, researchers are beginning to understand why people act and feel the way they do. When the central brain encounters a frightening situation, it releases stress hormones that prepare the body to fight or flee. The stomach contains many sensory nerves that are stimulated by this chemical surge – hence the “butterflies”. On the battlefield, the higher brain tells the gut brain to shut down. A frightened running animal does not stop to defecate, according to Dr. Gershon.
Fear also causes the vagus nerve to “turn up the volume” on serotonin circuits in the gut. Thus over stimulated, the gut goes into higher gear and diarrhea results. Similarly, people sometimes “choke” with emotion. When nerves in the esophagus are highly stimulated, people have trouble swallowing.