So a couple fruit flies walk into a bar...
Alex Brehm
Issue date: 2/5/10 Section: Opinions/Editorial
So a couple fruit flies walk into a bar…
Not a surprise for bartenders in at least one part of the country.
Biologists at the University of California, San Francisco (UCSF) have discovered that they can turn fruit flies into alcoholics. The experiment started out simply by setting up two food sources for the flies: one was a tube filled with just sugar and yeast, and one contained sugar and yeast with ethanol, the same alcohol you find in liquor and beer.
At certain periods, the researchers checked the tubes and documented how much flies ate from each tube - the tube with ethanol was always lower. Flies immediately showed a preference for consuming the ethanol-laced food.
The researchers continued their observations for five days. Interestingly, the flies' preferences for alcohol increased over time-every day, flies ate the ethanol food more and more, and ate the regular food less and less, like a freshman pushing the limits of his tolerance every Saturday night.
On the first day of the experiment, each fly ate an average of .7 ML (micro-liters) of ethanol food compared to .5 ML of plain food. But on the fifth day, flies ate 1 ML with ethanol compared to .4 without - like taking two and a half shots with every handful of chips.
Although flies were consuming alcohol in quantities that would actually impair their motor skills (even fruit flies can blackout), the researchers wanted to clearly demonstrate that the flies were addicted to ethanol. They decided to prove this by showing that flies would push through some harmful, negative stimulus to get to the alcohol.
They settled on the simple option of putting a chemical in the alcoholic food that would interact with the flies' antennae and signal danger from eating the food. It didn't matter to the flies; they still ate more alcoholic food than non-alcoholic.
Tally up what the researchers found: flies started out trying ethanol instead of plain food, built up a tolerance, ate it more and more and finally ignored obvious danger in order to get to the ethanol. It's America's classic drunken stereotype.
This is an important discovery for research into human alcoholism and addiction in general. Because fruit flies quickly reproduce and go through several generations in a short time, biologists use them to simulate genetic effects in humans. With the discovery that flies react to alcohol in a manner similar to humans, scientists can use fruit fly families to answer more questions about how people become addicted to drugs and alcohol.
The experiment also brings up questions about the notion of addiction in this country. To the researchers, the critical sign to call the flies "addicted" came when the flies overcame some signal of harm to get to the alcohol. Displaying a habit of preferring alcohol and imbibing until intoxication were other important factors in the experiment.
But does that downplay the nature of addiction in people? When do we say someone is "addicted" to something? And to what kinds of things do we say people can become addicted? The popular idea of addiction is much broader than the definition these scientists have used. The report itself admits, "No animal model will ever be perfect for alcoholism, because it is a human phenomenon influenced by social, cultural, and cognitive factors." Does this represent a breakthrough in medical research, or the beginning of a long distraction?
No matter what happens next, the next time I raise a glass, I'm toasting the fruit fly.
Alex Brehm is a sophomore economics major with the impetuous notion that he can just become a journalist.
Not a surprise for bartenders in at least one part of the country.
Biologists at the University of California, San Francisco (UCSF) have discovered that they can turn fruit flies into alcoholics. The experiment started out simply by setting up two food sources for the flies: one was a tube filled with just sugar and yeast, and one contained sugar and yeast with ethanol, the same alcohol you find in liquor and beer.
At certain periods, the researchers checked the tubes and documented how much flies ate from each tube - the tube with ethanol was always lower. Flies immediately showed a preference for consuming the ethanol-laced food.
The researchers continued their observations for five days. Interestingly, the flies' preferences for alcohol increased over time-every day, flies ate the ethanol food more and more, and ate the regular food less and less, like a freshman pushing the limits of his tolerance every Saturday night.
On the first day of the experiment, each fly ate an average of .7 ML (micro-liters) of ethanol food compared to .5 ML of plain food. But on the fifth day, flies ate 1 ML with ethanol compared to .4 without - like taking two and a half shots with every handful of chips.
Although flies were consuming alcohol in quantities that would actually impair their motor skills (even fruit flies can blackout), the researchers wanted to clearly demonstrate that the flies were addicted to ethanol. They decided to prove this by showing that flies would push through some harmful, negative stimulus to get to the alcohol.
They settled on the simple option of putting a chemical in the alcoholic food that would interact with the flies' antennae and signal danger from eating the food. It didn't matter to the flies; they still ate more alcoholic food than non-alcoholic.
Tally up what the researchers found: flies started out trying ethanol instead of plain food, built up a tolerance, ate it more and more and finally ignored obvious danger in order to get to the ethanol. It's America's classic drunken stereotype.
This is an important discovery for research into human alcoholism and addiction in general. Because fruit flies quickly reproduce and go through several generations in a short time, biologists use them to simulate genetic effects in humans. With the discovery that flies react to alcohol in a manner similar to humans, scientists can use fruit fly families to answer more questions about how people become addicted to drugs and alcohol.
The experiment also brings up questions about the notion of addiction in this country. To the researchers, the critical sign to call the flies "addicted" came when the flies overcame some signal of harm to get to the alcohol. Displaying a habit of preferring alcohol and imbibing until intoxication were other important factors in the experiment.
But does that downplay the nature of addiction in people? When do we say someone is "addicted" to something? And to what kinds of things do we say people can become addicted? The popular idea of addiction is much broader than the definition these scientists have used. The report itself admits, "No animal model will ever be perfect for alcoholism, because it is a human phenomenon influenced by social, cultural, and cognitive factors." Does this represent a breakthrough in medical research, or the beginning of a long distraction?
No matter what happens next, the next time I raise a glass, I'm toasting the fruit fly.
Alex Brehm is a sophomore economics major with the impetuous notion that he can just become a journalist.
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