Andrew Huberman· PhD
Subsequent experiments done by Dayu Lin in her own laboratory and other laboratories have shown that the ventromedial hypothalamus connected with a bunch of other brain areas that are interesting, And I'll talk about some of those in a little bit, but one of them that I want to call out now is the so-called PAG, the periaqueductal gray nucleus. This is a large structure in the back of the brain that houses things like neurons that can create opioids. We all know of the opioid crisis, but these are neurons that can produce endogenous, means made by the body, chemicals that can cause pain relief. You could understand why that might occur in a circuit for aggression, right? Even if one is the aggressor, it's likely that they may incur some physical damage and they'd want some pain relief. The PAG also is connected to a number of neural circuits that eventually, through several processing stations, excuse me, arrive at things like the jaws. And in fact, stimulation of the ventromedial hypothalamus can evoke biting and aggressive biting behavior.