Original title: Sex-Deprived Fruit Flies Turn to Alcohol, Perhaps to Fulfill a Physiological Demand for a Reward
ScienceDaily (Mar. 15, 2012) — After being deprived of sex, male fruit flies, known as Drosophila melanogaster, may turn to alcohol to fulfill a physiological demand for a reward, according to a study recently published in the journal Science. Troy Zars, an associate professor of biological sciences at the University of Missouri and neurobiology expert, said that understanding why rejected male flies find solace in ethanol could help treat human addictions.
"Identifying the molecular and genetic mechanisms controlling the demand for reward in fruit flies could potentially influence our understanding of drug and alcohol abuse in humans, since previous studies have detailed similarities between signaling pathways in fruit flies and mammals," Zars said.
In the study, male fruit flies that had mated repeatedly for several days showed no preference for alcohol-spiked food. On the other hand, spurned males and those denied access to females strongly preferred food mixed with 15 percent alcohol. The researchers believed the alcohol may have satisfied the flies' desire for physical reward.
Zars said the new discovery could lead to greater understanding of the relationship between the social and physical causes of substance abuse in humans.
"The authors provide new insights into a neural circuit that links a rewarding social interaction with a lasting change in behavior preference," Zars said.
Zars has been a faculty member at MU since 2002. He leads investigations of the molecular and systems level mechanisms of behavioral genetics in the fruit fly Drosophila melanogaster. He is well known for his experiments identifying molecular mechanisms and neural circuits that support behaviors in the relatively simple fly brain. His work has been published in leading scientific journals such as Science, Nature, Proceedings of the National Academy of Sciences, Current Biology, Learning and Memory, and Neuron.
The above story is reprinted from materials provided by University of Missouri-Columbia.
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G. Shohat-Ophir, K. R. Kaun, R. Azanchi, U. Heberlein. Sexual Deprivation Increases Ethanol Intake in Drosophila. Science, 2012; 335 (6074): 1351 DOI: 10.1126/science.1215932
Science 16 March 2012:
Vol. 335 no. 6074 pp. 1351-1355
Sexual Deprivation Increases Ethanol Intake in Drosophila
G. Shohat-Ophir 1,2,*, K. R. Kaun 1,2, R. Azanchi 1,2, U. Heberlein 1,2,*
1 Department of Anatomy, University of California, San Francisco, CA 94143-2822, USA.
2 Present address: Howard Hughes Medical Institute, Janelia Farm Research Center, Ashburn, VA 20174, USA.
* To whom correspondence should be addressed. (edited)
The brain’s reward systems reinforce behaviors required for species survival, including sex, food consumption, and social interaction. Drugs of abuse co-opt these neural pathways, which can lead to addiction. Here, we used Drosophila melanogaster to investigate the relationship between natural and drug rewards. In males, mating increased, whereas sexual deprivation reduced, neuropeptide F (NPF) levels. Activation or inhibition of the NPF system in turn reduced or enhanced ethanol preference. These results thus link sexual experience, NPF system activity, and ethanol consumption. Artificial activation of NPF neurons was in itself rewarding and precluded the ability of ethanol to act as a reward. We propose that activity of the NPF–NPF receptor axis represents the state of the fly reward system and modifies behavior accordingly.
Source: Science Mag