Video: After repeated exposure to alcohol fumes, fruit flies lose their sexual inhibitions and form 鈥渃ourtship chains鈥� of amorous males
Fruit flies that develop homosexual tendencies when drunk may help reveal how alcohol loosens human sexual inhibitions, claim researchers.
and her colleagues at Pennsylvania State University in University Park used a voyeuristic chamber dubbed the 鈥淔lypub鈥� to observe the influence of alcohol on the sexual behaviour of male Drosophila fruit flies.
The researchers got the flies drunk on the fumes of an ethanol-doused cotton pad placed at the base of the chamber, and filmed them using a camera held above the Flypub鈥檚 transparent ceiling.
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Male Drosophila will normally only court females, following them and vibrating their wings in a courtship 鈥渟ong鈥�, before attempting to copulate.
The first time they were exposed to alcohol, groups of male flies became noticeably intoxicated but kept themselves to themselves. But with repeated doses of alcohol on successive days, homosexual courtship became common.
From the third day onwards, the flies were forming 鈥渃ourtship chains鈥� of amorous males.
Blocked reward
Han argues that the drunken flies provide a good model to explore how alcohol affects human sexual behaviour. While the ability of alcohol to loosen human inhibitions is well known, it is difficult for scientists to study.
Han鈥檚 team used flies that were genetically modified so they cannot release dopamine in the brain unless the temperature exceeds 30 潞C, to test if the effects of alcohol were dependent on this brain chemical. Indeed they did show that the effect of alcohol on sexual behaviour depends on the presence of this neurotransmitter.
That makes sense, says Ulrike Heberlein, who studies the genetics of alcohol-induced behaviour at the University of California, San Francisco. She says dopamine is central to the neural reward circuits that evolved to motivate animals to seek food and sex, but which are also stimulated by drugs of abuse.
But do fruit flies really provide a good model for what happens in the inebriated human brain? Heberlein, who works on both flies and mice, believes they do. 鈥淲hat is cool is that there is such a similarity,鈥� she says. 鈥淚 am surprised by the parallels.鈥�
Journal reference: PLoS ONE (DOI: )
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