Oxytocin is often called the "love hormone" due to its role in encouraging social behaviors, love and long-term bonding. Now, scientists have discovered that it might have something to offer those with weak knees of a different kind. Research carried out at the University of Sydney has established that the hormone can curtail the intoxicating effects of alcohol in rats, suggesting that a sobriety pill for humans could one day become a reality.

Earlier experiments have demonstrated that oxytocin can halt the development of a tolerance to alcohol's sedative effects and also help to prevent cravings and addiction.

But this new research represents a much improved understanding of how oxytocin interacts with the brain when alcohol is flowing through the body. In their study, the scientists delivered the hormone to the brains of rats who had been given an intoxicating dose of alcohol. Observing the behavior of the rodents, they found that the oxytocin served to prevent the sloppy movements we normally associate with being drunk.

"In the rat equivalent of a sobriety test, the rats given alcohol and oxytocin passed with flying colors, while those given alcohol without oxytocin were seriously impaired," says Dr Michael Bowen, from the University of Sydney's School of Psychology and lead author on the study.

The researchers say the reason for this is a function of the oxytocin that stops the alcohol from reaching parts of the brain that facilitate intoxication of the body. More specifically, the process sees oxytocin block brain receptors known as delta subunit-containing GABA-A. This was a particularly surprising finding for the team, as oxytocin had been thought to bind predominantly to its own receptors and those of a specific, closely related peptide called vasopressin.

"Alcohol impairs your coordination by inhibiting the activity of brain regions that provide fine motor control," says Dr Bowen. "Oxytocin prevents this effect to the point where we can't tell from their behavior that the rats are actually drunk. It's a truly remarkable effect."

While the hormone holds promise as a cure for loose lips and looser dancefloor moves, the researchers emphasize that it wouldn't actually affect blood-alcohol levels in those treated. So while oxytocin might stop the alcohol from turning you into an uncoordinated, stumbling mess, you would still find yourself in trouble with the law if you tried to drive home drunk.

How this research translates to humans is the next question the scientists are set to tackle. Central to this will be the method of drug delivery and working out how an effective dose can reach the brain. They plan on undertaking human studies in the near future.

"If we can do that, we suspect that oxytocin could also leave speech and cognition much less impaired after relatively high levels of alcohol consumption," Dr Bowen said.

The research was published in the journal Proceedings of the National Academy of Sciences.

You can see the tipsy and not-so-tipsy rats in action in the video below.