Research identifies biomarker for compulsive consumption.
Researchers have found mice that binge drink when given free access to alcohol have a previously unidentified brain circuit that is out of whack.
The wiring error may mean the rodents don’t experience the negative outcomes of drinking, such as bad feelings and pain hypersensitivity, which pushes them to over imbibe.
The finding, published in the journal Science, could fuel new research to hunt down a similar circuit in people with alcohol use disorders.
The researchers, led by neurobiologist Kay Tye from the Salk Institute for Biological Studies, US, point to the puzzling statistic that while 80% of people will try alcohol, less than 30% go on to become compulsive drinkers.
“So many people are exposed to alcohol at some point in their lives, but why is it that some people can drink casually, just for fun, and other people develop alcohol use disorders?” asks Tye.
Excess alcohol is a factor in more than 200 diseases, yet only half of heavy drinkers in the US can cut down or quit, despite the heavy toll. Tye’s group set up a meticulous experiment in mice to find out why.
First they gauged the natural propensity to binge drink. The mice were given access to plain alcohol laced with increasing amounts of quinine, a bark derivative that gives tonic water its bitter taste.
The quinine top-up called last drinks for some of the mice. But one group remained unfazed – they not only drank more straight booze, they simply carried on guzzling as the drink got tainted with tonic.
The binge-like behaviour roused the researchers’ suspicion that something might be amiss in a brain bit called the periaequeductal grey (PAG). It’s a ring of tissue in the midbrain that modifies behaviour by punishing it with, among others, negative feelings.
The team also knew changes in the medial prefrontal cortex (mPFC) – which deals with judgment, decision making and keeping a lid on impulses – are linked to compulsive drinking.
Could something be up with the crosstalk between those two zones, they wondered?
Read the full story in Cosmos magazine here