Caroline has had a long, trying week at work. Her desk was overloaded with paperwork to complete, her boss threw an extra project onto her plate, and—on top of all that—she had to find time to study for her last college final. Needless to say, she was ready for Friday on Monday, and when that night finally rolled around, she had no problem letting loose. She bought a bottle of wine and opened it with her friends at promptly 9 p.m., just as her excitement began to peak.
It’s no coincidence that this character (Caroline) grew more eager to drink as the evening progressed. We see this happen every day—the sun goes down, the bars stay open, and people crack open a beer or pop open a bottle of wine. It seems to be engrained in our minds that drinking alcohol is reserved for nighttime or perhaps more widely accepted at nighttime. Well, as it turns out, there’s another reason we, like Caroline, feel more inclined to drink as night falls: there is a link between our brain’s immune system and the desire to drink alcohol in the evening, according to a new study, “The efficacy of (+)-Naltrexone on alcohol preference and seeking behavior is dependent on light-cycle” published in Brain, Behavior, and Immunity.
In order to make this discovery, researchers at the University of Adelaide conducted laboratory studies using mice and alcohol. They found that after giving the mice a drug that blocks communication from the immune system in the brain, they were able to successfully counter the mice’s impulse to drink alcohol. The groundbreaking study is now published as the first research of its kind to find a connection between our brain’s immune system and the desire to consume alcohol at night.
Lead author of the study Jon Jacobsen, who is also a PhD student in the University of Adelaide’s Discipline of Pharmacology, expresses the world’s need to better understand the drive behind drinking. “Alcohol is the world’s most commonly consumed drug, and there is a greater need than ever to understand the biological mechanisms that drive our need to drink alcohol,” he told NeuroscienceNews.
Jacobsen went on to explain that we get the most from drinking alcohol at night because, “our body’s circadian rhythms affect the ‘reward’ signals we receive in the brain from drug-related behavior, and the peak time for this reward typically occurs during the evening.” Going off of this known truth, he and his team then decided to test how the brain’s immune system comes into play and sought to find out if they could intervene.
According to senior author Mark Hutchinson, who is also a Director of the ARC Centre of Excellence for Nanoscale BioPhotonics at the University of Adelaide and leader of the Neuroimmunopharmacology lab where the study was held, this is only the beginning of research related to alcohol and the brain’s immune system. He says that their findings prove the need to conduct further research into understanding the effects on human drinking behavior.