Recurring ethanol exposure induces disinhibited courtship in Drosophila.
Alcohol has a strong causal relationship with sexual arousal and disinhibited sexual behavior in humans; however, the physiological support for this notion is largely lacking and thus a suitable animal model to address this issue is instrumental. We investigated the effect of ethanol on sexual behavior in Drosophila. Wild-type males typically court females but not males; however, upon daily administration of ethanol, they exhibited active intermale courtship, which represents a novel type of behavioral disinhibition. The ethanol-treated males also developed behavioral sensitization, a form of plasticity associated with addiction, since their intermale courtship activity was progressively increased with additional ethanol experience. We identified three components crucial for the ethanol-induced courtship disinhibition: the transcription factor regulating male sex behavior Fruitless, the ABC guanine/tryptophan transporter White and the neuromodulator dopamine. fruitless mutant males normally display conspicuous intermale courtship; however, their courtship activity was not enhanced under ethanol. Likewise, white males showed negligible ethanol-induced intermale courtship, which was not only reinstated but also augmented by transgenic White expression. Moreover, inhibition of dopamine neurotransmission during ethanol exposure dramatically decreased ethanol-induced intermale courtship. Chronic ethanol exposure also affected a male's sexual behavior toward females: it enhanced sexual arousal but reduced sexual performance. These findings provide novel insights into the physiological effects of ethanol on sexual behavior and behavioral plasticity.
Lee
Hyun-Gwan
HG
Department of Biology, Huck Institute Genetics Graduate Program, Pennsylvania State University, University Park, Pennsylvania, USA.
Kim
Young-Cho
YC
Dunning
Jennifer S
JS
Han
Kyung-An
KA
D000222:Adaptation, Physiological; D000818:Animals; D004330:Drosophila / Q000502:physiology*; D000431:Ethanol / Q000008:administration & dosage*; D005260:Female; D008297:Male; D012726:Sexual Behavior, Animal
D000431:Ethanol