小白鼠的骨髓移植实验

A strain of mutant mice groom compulsively til they seriously injure themselves. The condition is considered a good animal model for OCD, and it’s similar to the human disorder trichotillomania, where people pull out their own hair. Now researchers have successfully treated this pathological behavior in the mice—with a bone marrow transplant. The work, led by Nobel Laureate Mario Capecchi, was published in the journal Cell.

The mouse condition is related to immune system cells called microglia. These cells originate in the bone marrow and wind up in the brain, where their job is to fight off infections. But a genetic mutation leads to defective microglia, which drive the mice to perform the odd, self-mutilating behavior.

The researchers gave 10 mutant mice bone marrow from healthy mice. And the presence of normal microglia stopped the compulsion. It’s compelling evidence for the long-proposed link between the immune system and certain psychiatric disorders.

Capecchi warns that bone marrow transplants are too risky to be commonly used against, for example, OCD. Rather, a fuller understanding of the immune system-mental illness connection should produce new treatments.

—Steve Mirsky