When Fruit Flies Get Drunk, They Act a Lot Like Us

Like humans, drunken fruit flies feel like they're ready for lift-off... at first. Cornel Constantin/Shutterstock

Birds do it. Bees do it. Even educated fleas do it.

Let's all fall into a drunken stupor.

Of course, that's not usually the aim of getting your drink on. Rather, there's the initial feel-good factor at the onset of drinking booze. You know, when the people around you are your best friends in the whole wide world forever. The stupor — and the hangover — come later.

That journey into drunkenness is a well-trod path that humans have trudged along for millennia. But it's also an experience shared by many other animals.

Birds, bears and even elephants get drunk — though not intentionally like humans.

The experience, however, is very much the same. In fact, scientists at Scripps Research Institute recently plied fruit flies with booze and noticed a similar routine: Euphoria, energy and then that all-too-familiar dulling of the senses.

The study, published this month in Journal of Molecular Biology, casts fresh light on how the brain responds to alcohol and produces that universal effect we know as drunkenness.

"They act just like people," lead author Scott Hansen, a professor at Scripps Research Institute, noted in a statement. "They start losing coordination. They literally get drunk."

The fruit flies revealed that alcohol has unique molecular properties that interact with neurons.

Specifically, an enzyme in the brain called phospholipase D2, or PLD2, serves as a link between ethanol molecules (your cocktail) and the fat on the surface of nerve cells.

Essentially, the meeting between alcohol molecules and nerve cells in the brain produces a kind of anesthetic or sedative.

Drunken fruit flies, like humans, feel nothing — which for many of us, can be a very desirable feeling.

After a period of "hyperactivity" — and, we can only assume drunken games of chance and other bad decisions — the sloshed insects settled down dramatically.

Their buzz was effectively killed.

Scientists also engineered a new fruit fly with brain cells that didn't recognize PLD2. When dosed with alcohol, the altered insects didn't show any signs of being hammered at all — which seemed to confirm the key role PLD2 plays in feelings of drunkenness.

That these fruit flies never felt a boozy buzz at all could prove a game-changer for humans with addiction. By proving that alcohol doesn't go to work directly on the brain as previously thought, scientists may be able to interrupt the circuit it uses to get there — namely, the PLD2 pathway.

Imagine not being able to drink yourself senseless. By killing that buzz, scientists may be able to save lives.

"It has definitely led to some different ways of thinking about alcohol intoxication at the molecular level," Hansen explained. "Most scientists thought alcohol had a direct effect. Blocking the enzyme in flies shows that's not likely true."

"Also," he added, "Understanding this pathway could give insight as to why people use alcohol for pain management."