A study conducted by researchers at the University of California, San Francisco (UCSF), and the Janelia Farm Research Center revealed curious behavior in male Drosophila melanogastercommonly called fruit flies: if rejected from females, they tend to choose alcoholic foods.
This phenomenon has been attributed to a brain signaling molecule called neuropeptide F (NPF). The researchers observed that rejected males show a significant decrease in SFN in the braina condition associated with increased seeking of alternative rewards, such as alcohol.
On the contrary, in flies that manage to mate, the levels of NPF remain stablereducing the likelihood of preferring alcoholic foods. This behavioral response is similar to the functioning of neuropeptide Y in humans, an element that potentially links the pursuit of compensatory pleasures, such as alcohol or drug use, to states of emotional or social deprivation.
The interesting link between emotional states and the search for gratification
The experiment, published in the journal Sciencewas structured in two phases. First, the researchers introduced a group of male flies into a case with virgin and already fertilized females. While virgin females easily accepted courtship, fertilized ones they rejected the malesgradually leading them to lose interest in mating.
Subsequently the males were presented with two food choices: a container with normal food and one with an alcohol content of 15%. “Disappointed” flies preferred the alcoholic food significantly more than “satisfied” males (70% versus 50%).
This research suggests that the brain reward system of animals, including humans, may have retained some fundamental elements through evolution. Identifying the genetic and molecular bases that govern reward seeking can help better understand human addictions, which are often influenced by a combination of biological and social factors.
Furthermore, the researchers found that artificially increasing NPF levels in the rejected male midges was possible reduce their interest in alcoholic food. This result opens the way to new hypotheses on modulation of behaviors related to addictionoffering ideas for possible therapeutic interventions in the human context.
