Immune system controls behaviour of drunks

Alcohology

It has been thought that alcohol directly affects the nerve cells in the brain. But, researchers at the University of Adelaide in Australia now found that the behavioural effects of alcohol come from the immune system instead.

“It’s amazing to think that despite 10,000 years of using alcohol, and several decades of investigation into the way that alcohol affects the nerve cells in our brain, we are still trying to figure out exactly how it works,” study author Mark Hutchinson was quoted as saying by LiveScience.

Sedation and reduced muscle coordination are known to be among the behavioural effects of alcohol, and are the ones that lead to traffic accidents and morning-after bumps and bruises.     However, it turns out that scientists may have been looking in the wrong cells of the body for the cause of these behaviours, the researchers said.

For their study, published in the British Journal of Pharmacology, the researchers genetically engineered mice to be able to “hold their liquor”, in a sense. The scientists focused on deactivating TLR4 — the “Toll-like receptor 4” — a switch of sorts that activates the body’s innate immune system, which automatically provides responses, including fever and inflammation, to an infection. When TLR4 is activated, immune cells in the brain called glia send out an inflammation signal, which may be a key way alcohol causes behavioural changes (like stumbles and slurs) and long-term brain damage.

It was found that genetically engineered mice with inactive TLR4 proved resistant to the behavioural effects of alcohol while they were drunk, researchers said.