Abstract
Dysregulated motivation to consume psychoactive substances leads to addictive behaviors that often result in serious health consequences. Understanding the neuronal mechanisms that drive drug consumption is crucial for developing new therapeutic strategies. The fruit fly Drosophila melanogaster offers a unique opportunity to approach this problem with a battery of sophisticated neurogenetic tools available, but how they consume these drugs remains largely unknown. Here, we examined drug self-administration behavior of Drosophila and the underlying neuronal mechanisms. We measured the preference of flies for five different psychoactive substances using a two-choice feeding assay and monitored its long-term changes. We found that flies show acute preference for ethanol and methamphetamine, but not for cocaine, caffeine or morphine. Repeated intake of ethanol, but not methamphetamine, increased over time. Preference for methamphetamine and the long-term escalation of ethanol preference required the dopamine receptor Dop1R1 in the mushroom body. The protein level of Dop1R1 increased after repeated intake of ethanol, but not methamphetamine, which correlates with the acquired preference. Genetic overexpression of Dop1R1 enhanced ethanol preference. These results reveal a striking diversity of response to individual drugs in the fly and the role of dopamine signaling and its plastic changes in controlling voluntary intake of drugs.
Highlights
Dysregulated motivation to consume psychoactive substances leads to addictive behaviors that often result in serious health consequences
X-ray crystallography showed that methamphetamine and cocaine bind to the Drosophila dopamine t ransporter[21], which is the primary molecular target of these drugs in mammals[22]
We found that flies prefer to drink ethanol and methamphetamine, but not cocaine, caffeine and morphine
Summary
Dysregulated motivation to consume psychoactive substances leads to addictive behaviors that often result in serious health consequences. Genetic overexpression of Dop1R1 enhanced ethanol preference These results reveal a striking diversity of response to individual drugs in the fly and the role of dopamine signaling and its plastic changes in controlling voluntary intake of drugs. The fruit fly Drosophila melanogaster has been established as a useful genetic model organism for decades These flies show many characteristic responses common in humans, especially toward ethanol. Exposure of the flies to vapored ethanol make them first hyperactive, uncoordinated, and eventually s edated[4,5,6] They develop tolerance after repeated exposure[7,8] and show withdrawal-like symptoms when ethanol is suddenly withheld after chronic exposure[9]. Because these drugs often cause compulsive drug seeking behavior in humans, it is tempting to hypothesize that flies may choose to consume these drugs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
