Using genetic engineering, researchers have created an obsessive-compulsive disorder (OCD) -- like set of behaviors in mice and reversed them with antidepressants and genetic targeting of a key brain circuit. The study, by National Institutes of Health (NIH) -- funded researchers, suggests new strategies for treating the disorder.
Researchers bred mice without a specific gene, and found defects in a brain circuit previously implicated in OCD. Much like people with a form of OCD, the mice engaged in compulsive grooming, which led to bald patches with open sores on their heads. They also exhibited anxiety-like behaviors. When the missing gene was reinserted into the circuit, both the behaviors and the defects were largely prevented.
The gene, SAPAP3, makes a protein that helps brain cells communicate via the glutamate chemical messenger system.
"Since this is the first study to directly link OCD-like behaviors to abnormalities in the glutamate system in a specific brain circuit, it may lead to new targets for drug development," explained Guoping Feng, Ph.D., Duke University, whose study was funded in part by the National Institute of Neurological Disorders and Stroke (NINDS), the National Institute of Mental Health, and the National Institute of Environmental Health Sciences (NIEHS). "An imbalance in SAPAP3 gene-related circuitry could help explain OCD."
The researchers reported on their discovery in the August 23, 2007, issue of Nature.
Jules Asher or Kevin Sisson, NIMH
NIMH press office
Natalie Frazin, NINDS
Robin Mackar, NIEHS
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