As reported in Scientific American a few days ago, in vitro research performed by scientists at the University of Pittsburgh has shown that, if the anesthetic molecule is small enough, it will bind with a pocket in amyloid beta peptides. This binding results in a conformational change to the molecule, making it possible for them to clump together with other similarly misshapen peptides. Amyloid plaques, which are clumps of these proteins, are involved in Alzheimer's disease, though it is unknown at this time whether they are a cause or an effect of the disease. Some anesthetics are too big to fit into the peptide's "pocket", and therefore do not cause plaque formation. The examples provided in the article are as follows: "Halothane had the greatest clumping effect, yet it is rarely used in
North America and Europe. Two other anesthetics–isoflurane and
propofol–also cause clumping, but their effect is not as severe.
Another one, called thiopental, does not cause clumping at all because
its molecule is too big to fit inside the peptide's pocket."
The next step is to try to reproduce these results in a mouse model of Alzheimer's, to see if the in vivo effects are the same as the in vitro. Certainly an interesting area of research to keep an eye on.