Sci at Neurotic Physiology writes about a study with some surprising findings: lab rights ALWAYS pick saccharin over cocaine. Sci notes a few minor issues with the study, but highlights the broader implication:
Well, this could be a bug, or a feature, of self-administration in rodents. If it DOES turn out that saccharin is more rewarding than cocaine in rats, and this is not the case in humans (you could probably test parts of thing in some humans, which would be interesting), well, this could be a difference between humans and rats. It could ALSO be an issue with the self-administration model itself. Some people have criticized drug self-administration in rats, because it doesn’t lead to the rat banging on the lever constantly in desperation or other things we would assume are associated with addiction. This could be just that rats aren’t in for that sort of thing. It could ALSO be that there are problems with the doses we give the rats, the schedules they can administer drug under, or even the environments the drug is administered in.
(via Social Physicist)