Electron spin changes as a general mechanism for general anesthesia?

How does consciousness work? Few questions if any could be more profound. One thing we do know about it, jokes biophysicist Luca Turin, is that it is soluble in chloroform. When you put the brain into chloroform, the lipids that form nerve cell membranes and the myelin that insulates them will dissolve. On the other hand, when you put chloroform into the brain, by inhaling it, consciousness dissolves. It is hard to imagine a satisfying explanation of consciousness that does not also account for how anesthetics like chloroform can abolish it.

Lipid solubility appears to be one key clue to anesthesia. The empirical cornerstone of anesthesiology is a 100 year old rule of thumb known as the Meyer-Overton relationship. It provides that the potency of general anesthetics (GAs), regardless of their size or structure, is approximately proportional to how soluble they are in lipids. Since that time, studies have suggested that GAs can also bind to lipid-like parts of proteins, presumably those near or embedded within cell membranes.

The first real stab at explaining the "how" of anesthetics, as opposed to just the "where", has now been taken by Turin and his colleagues Efthimios Skoulakis and Andrew Horsfield. Their new work, just published in PNAS, suggests that volatile anesthetics operate by perturbing the internal electronic structure of proteins. This would lead to changes in electron currents in those proteins, in cells, and in the organism. They don't just theorize about these effects, they actually measure the electron currents in anesthetized flies using a technique known as electron spin resonance (often called electron paramagnetic resonance).