San Diego scientists have discovered that chronic alcoholism can partly be explained by immune cells in the brain. These cells — called microglia — are important for brain health, but when they are over-activated by stressors like constant alcohol consumption, they can rewire the brain in a negative way.
The research, which came out in Biological Psychiatry, shows that alcoholism isn’t just a function of reward responses in the brain or genetics. When Scripps researchers looked at excessive alcohol consumption in mice, they saw a change in neurological activity.
Microglia, which are responsible for reducing inflammation and for cleaning out the brain of hazardous materials, can show negative effects when they are overactivated. And that overactivation changes the wiring in the brain, increasing the drive to drink and creating an addiction cycle.
“These microglia could actually — instead of being the friends of the brain — could be actually contributing to this loss of control over alcohol intake,” said Marisa Roberto, neuroscientist at Scripps Research and lead author on the paper.
The over-activation of these microglia have been shown in other research to contribute to diseases like Alzheimers.
“With alcohol and repeated excessive drinking, we show that you can have an increase in activation of the microglia. And that brings some negative aspects of microglia. So some neurotoxic effects,” she said.
“[That] contributes to imbalance and dysregulation that occur in the brain… [that creates] anxiety like behavior that’s really the characteristic of the pathology of alcoholism, alcohol use disorder...so, we found a causal link between microglia and the transition to dependence.”
Roberto says that means a potential therapy for suppressing alcoholism could be drugs that specifically target these immune cells.
“If we can control this progressive increase in microglia activation ... I really believe we could at least alleviate the problem,” she said.
Roberto says she’s excited to test out microglia targeting drugs in human clinical trials.
