The Brain, Nucleus Accumbens

The Stanford scientists then focused on the nucleus accumbens, a brain structure known to be involved in computing the behavioral strategies that prompt us to seek or avoid things that can affect our survival. They found that chronic pain permanently changed certain connections to the nucleus accumbens, causing an enduring downshift in the excitation transmitted by them. Importantly, Malenka’s group showed that a particular brain chemical called galanin plays a critical role in this enduring suppression of nucleus accumbens excitability.

Galanin is a short signaling-protein snippet secreted by certain cells in various places in the brain. While its presence in the brain has been known for a good 60 years or so, galanin’s role is not well-defined and probably differs widely in different brain structures. There have been hints, though, that galanin activity might play a role in pain. For example, it’s been previously shown in…