When I was in a band, our drummer would show up to practice drunk before passing out on his snare. He seemed to be forever hung over. After checking out Fulton Crews’ research on the effects of binge drinking, I’m not sure “forever” is an exaggeration.

Click to read photo caption. Image courtesy of Fulton Crews.

Crews studied the effects of alcohol on rats, mice, and humans, and found that binge drinking can cause the kind of brain damage that impairs decision-making long after the drinking stops.

In one experiment, Crews showed that adult rats that had been exposed to binge levels of alcohol three weeks prior could learn things effectively but had trouble relearning.

Crews’ researchers placed a control rat in a tub of water. The rat easily learned to find a platform just below the water’s surface. The other rat — now sober for three weeks — also easily learned to find the platform.

When the platform was moved to a different place, the control rat swam to the old location, couldn’t find the platform, spun around once, and then searched briefly before finding the platform. The alcohol-exposed rat swam to the old location and couldn’t find the platform, but instead of searching elsewhere, it circled the old location repeatedly. Eventually the rat gave up and swam slowly along the side of the tub until researchers removed it. This behavior suggests that relearning processes are disrupted long after a binge-drinking episode.

Some of Crews’ other studies have shown that binge drinking can cause loss of neurons and inhibition of neurogenesis — the process by which stem cells form new neurons. Such changes in brain structure cause subtle behavioral changes long after binge drinking.

“Repeated behaviors and difficulty relearning can happen when you have damage to the frontal cortex,” Crews says. “You can’t pay attention and you don’t think through decisions. You don’t think, ‘Where’s that platform, I just looked where I thought it was?’ You keep doing the same thing repeatedly without thinking about it.”

In other studies on the effects of binge drinking, Crews found that cytokines — a group of proteins — were released in the liver and traveled to the brain, where they are toxic to neurons and stem cells. Crews found that cytokine levels in blood serum and the liver returned to normal after one day, whereas cytokine levels in the brain stayed elevated for months. This long-lasting increase in brain cytokines could result in long-lasting changes in brain function, similar to the disrupted learning of the rats exposed to binge levels of alcohol, Crews says.

But mice and rats aren’t men, so Crews studied human postmortem brains that he got from a donor program in Australia. He found that cytokine levels were much higher in the brains of alcoholics than in moderate drinkers. Alcoholics are known to have smaller brains due to chronic drinking, but Crews is the first to discover increased cytokines in the brains of alcoholics. Cytokines regulate anxiety, depression, mood, and drinking behavior, all of which are associated with alcoholism.

His lab is still studying how binge drinking, cytokines, and neurotoxicity might change behavior. Crews says that binge drinking might disrupt the parts of the brain that normally inhibit impulses. These brain regions typically promote thoughtful reflection on the consequences of actions.

Crews says, “It’s possible that binge drinking changes the cerebral cortex and with each binge a person becomes more impulsive, and then compulsive, and then he’s stuck. He’s addicted.”

Fulton Crews is the director of the Bowles Center for Alcohol Studies.