Oddly enough, we are not talking about humans but about fruit flies ( Drosophila melanogaster ). A surprising study published in Science reveals that male flies deprived of sexual intercourse are more likely to choose foods that contain ethanol. The researchers suspect that a neurotransmitter called neuropeptide F (NPF) could be involved in this response.
Scientists at the University of California already knew that alcohol consumption activates certain brain circuits related to the sensation of pleasure in fruit flies . That is why they decided to go one step further and analyze how different types of rewarding experiences are connected at the brain level. First, they put male flies in two types of situations. The luckiest ones shared a vial with several receptive females with whom they could copulate. The other half of the males were placed with a single non-receptive female. After 4 days in a row of experiencing sexual success or failure, as the case may be, the flies were placed in vials containing two types of food: one with 15 percent ethanol and the other alcohol-free.
The researchers expected that all the flies would choose alcoholic food, but surprisingly only those that had “gotten pumpkins” favored it. To try to explain these data, they decided to measure the levels of NPF in insects, since in previous experiments it had been seen that this neurotransmitter is related to alcohol consumption . And they found that rejected flies had half the NPF of those who had had sex.
Alcohol consumption and depression
Galit Shohat-Ophir, one of the authors of the work, explains that NPF levels could condition the choice of alcohol consumption, since flies with less NPF would tend to choose food with ethanol to recover normal levels.
In addition, in mammals there is an analogous protein, called neuropeptide Y, whose levels decrease in depressed individuals or those who suffer some type of post-traumatic stress, and which also influence the consumption of alcohol and drugs.
The researchers affirm that there are still many aspects to be understood, such as the mechanism by which NPF levels increase after a sexual experience.
