Biological Basis for Lonlieness [...]

While the public, private and volunteer sectors in Britain are mobilizing to address loneliness, researchers are deepening their understanding of its biological underpinnings. In a paper published earlier this year in the journal Cell, neuroscientists at the Massachusetts Institute of Technology identified a region of the brain they believe generates feelings of loneliness. The region, known as the dorsal raphe nucleus, or D.R.N., is best known for its link to depression.

Kay M. Tye and her colleagues found that when mice were housed together, dopamine neurons in the D.R.N. were relatively inactive. But after the mice were isolated for a short period, the activity in those neurons surged when those mice were reunited with other mice.

“This is the first time we’ve found a cellular substrate for this experience,” said Dr. Tye, an assistant professor at the Picower Institute for Learning and Memory at M.I.T. and a senior author of the paper. “And we saw the change after 24 hours of isolation.” (Source)