Key to psychological disorder may lie in the immune system

A type of cell that is known to protect the brain against infection could be involved in a form of psychological disorder, a new study reveals. What's more, restoring normal populations of these cells by transplantation can cure abnormal behaviour in mice.

Microglia are highly branched immune cells that constantly move around and scavenge the brain for debris and pathogens. Researchers have now shown that a genetic defect that reduces the number of these cells causes excessive grooming in mice. The behaviour is similar to that observed in trichotillomania in humans — an obsessive-compulsive spectrum disorder that compels people to pull out their hair. "No connection had ever been made between microglia and behaviour," says Mario Capecchi at the University of Utah in Salt Lake City, whose team published the findings today in Cell1.

Scientists had presumed that abnormal behaviour stems from impaired neural function or brain development, says Christopher Pittenger, who studies the neural basis of psychiatric conditions at Yale University in New Haven, Connecticut. "To find that it has to do with microglia is a big surprise," says Pittenger, who was not involved in the new study. ...

via Key to psychological disorder may lie in the immune system : Nature News.

I was just hearing that probiotics may correct some mental disorders.