Loneliness is driven by dopamine release from dorsal raphe nucleus neurons, motivating social seeking.

“And it really places social interactions as right up there in the list of things that we could consider so vital for our survival and for our health. Things like food, water, social interactions really sit within a top tier amongst each other, and they use the same common circuitry, dorsal raphe dopamine neurons, in addition to other structures, in order to create this drive, to seek out certain types of stimuli.”

“So what we think of as loneliness as this big kind of dark cloud, or, you know, fog in our psychological landscape, boils down to a very small set of neurons, releasing a specific neurochemical for motivation.”

“What they did is they were able to selectively activate the dopamine neurons in the dorsal raphe nucleus. And when they did that, they induced a loneliness-like state. Now, how did they know it was a loneliness-like state? They knew because it motivated the seeking out of social connections.”

“this incredible neural structure that is the dorsal raphe nucleus and this small collection of neurons, the dopamine neurons of the dorsal raphe because while it's a small collection, they are very powerful.”

“And it is this dorsal rafé nucleus and the dopamine neurons in that nucleus that underly the bond that is social friendship and all types of social bonds.”