Drosophila Drink the Pain Away too

Let's play with some stereotypes here: females who have been recently are about half the reason Ben and Jerry's exists. The other half is probably dumped guys, but they won't admit it, making proving my entirely invented statistics hard to do. The stereotypical male behavior breakup behavior is to go to a bar and get schwasted. Turns out, they might be sitting next to some Drosophila melanogaster at the bar doing the exact same thing.

A recent study out of the University of California by Dr. Shohat-Ophir showed that male fruit flies whose sexual advances got rejected were about 20% more likely to drink a food supply containing alcohol. They also drank 4 times as much as their progenitor-producing peers. To make sure these flies couldn't catch a break, the unlucky flies were placed in a vial with a female who had already mated, so she would continually reject the male's advances. The lucky flies were placed in vials containing 20 virgin female flies to 4 virgin males, ensuring they mated multiple times.

Naturally, these results raised questions of what in the flies' neurobiology was stimulating this desire for ethanol. They took the rejected male brains and measured how much neuropeptide F (NPF) there was, as NPF has been previously linked to alcohol preference. The levels of NPF were inversely related to alcohol desire: mated flies had higher levels of NPF than the unmated flies. In order to verify this, they lowered levels of NPF in mated males and, sure enough, saw the mated males drinking more alcohol. This proved that NPF is sufficient to dictate alcohol preference in fruit flies.

Humans have a similar protein, called neuropeptide Y (NPY). In depressed people and those experiencing post-traumatic stress disorder, NPY levels are indeed decreased, and certain alternate versions of NPY have been linked to alcoholism in humans. However, in both fruit flies and humans, how social cues like rejection are translated into NPF/Y levels is unknown, and how NPF/Y affect alcohol consumption is a black box as well.