— the nerve cells in the esophagus, stomach, small and large intestines that communicate hunger to the brain.


     [There are] sophisticated processes that take place in our digestive tracts to let us know when we're hungry. There, a collection of nerve cells work together and communicate much as the neurons in our brain do. It's essentially an autonomous and self-governing second brain that we all carry in our belly.

The " gut brain ," formally known as the enteric nervous system, is made up of some 500 million nerve cells, as many as there are in a cat's brain. They help to control muscular contractions in the gut as well as the secretions of glands and cells. And they help balance hunger and satiety, or the sense of being full, communicating those states to the big brain.

See article at: WSJ 25Jan11 – Hungry? Your Stomach Really Does Have a Mind of Its Own



It turns out there's a collection of nerve cells — as much as in a cat's entire brain — that call the human digestive tract home. These cells, which make up the "gut brain," communicate with the actual brain to signal hunger and fullness.

See article at: Time News Feed 26Jan11 – The Big New Diet Fad: Playing Mind Games With Your Stomach