Humans, like all social animals, have a fundamental need for contact with others. This deeply ingrained instinct helps us to survive; it’s much easier to find food, shelter, and other necessities with a group than alone. Deprived of human contact, most people become lonely and emotionally distressed.
In a study, MIT neuroscientists have identified a brain region that represents these feelings of loneliness. This cluster of cells, located near the back of the brain in an area called the dorsal raphe nucleus (DRN), is necessary for generating the increased sociability that normally occurs after a period of social isolation, the researchers found in a study of mice.