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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. [http://bit.ly/a4znGN]
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
[The above text is an exact transcript of this podcast.]
For a profile of Mario Capecchi, go to http://bit.ly/9SEy4M
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3 Comments
Add CommentI am a doctor.I believe there are some connections between immune system and mental illness.Microglia originating in the bone marrow and winding up in the brain maybe the key.
Reply | Report Abuse | Link to thisWhen our immune system is responding to attack, that is trauma. Unresolved trauma results in mental illness symptoms, PTSD. Perhaps almost all mental illness symptoms are from PTSD, when you include multigenerational genetics. So, the marrow transplant is healing the unresolved trauma in the immune system.
Reply | Report Abuse | Link to thisI'm not a doctor, but I do suffer from Trichotillomania. I have pulled my eyebrows for over 20 years, and I can "feel" my scalp much of the time so it's hard to resist scratching and pulling there too. Most trich sufferers have been exposed to the idea (and many support it) that trich is not at all an OCD but rather is an overactive immune response, perhaps to byproducts of the common skin yeast Malassezia. And, there has been active lobbying by various trich groups to have this disorder reclassified.
Reply | Report Abuse | Link to thisA PhD at Columbia who suffers figured it out, and has prescribed a diet (google John Kender diet or malassezia diet) to reduce the infestation/triggers. I can attest that when my systemic yeast is high (foods, antibiotics, illness - in particular a salmonella infestation) it causes my trich to go bonkers.
I wish doctors knew more about immune response system overall...it seems that there might be a number of "unexplained" or misdiagnosed syndromes that are actually just essentially allergic reactions. A friend of mine was misdiagnosed with "chronic sinus infection" and given a surgery that ultimately left her brain damaged, only to find out that it was actually an overactive immune response to a massive systemic yeast infection caused by a previous bowel infection that left her imbalanced and uncorrected. It was apparently pretty easy to detect that her immune system was on "hyperactive response" using a simple skin patch test similar to regular allergy testing. Now, watching everything she eats and taking anti-yeast meds, she's finally seeing improvement in her sinuses.
@mikemikef PTSD is a very different thing. Trich is a body-focused disorder usually indicated by chronic hair pulling, skin scratching and similar reactions.