An unusually anxious, compulsively overgrooming mouse is presented in the August 23, 2007 issue of Nature (Vol. 448, No. 7156, pp. 894-900) as a possible model for obsessive compulsive disorder (OCD). Mice in which the gene known as Sapap3 has been deleted show many of the characteristic behaviours associated with OCD, and may be useful to researchers looking at the neuropathology and treatment of the disorder.
OCD is an incapacitating psychiatric disorder affecting around 2% of the world's population. It is characterized by persistent intrusive thoughts (obsessions), repetitive actions (compulsions) and excessive anxiety. Although the symptoms are well known, the neurobiological basis of the disorder is less clear. In the current study, Guoping Feng and colleagues show that deleting Sapap3 in mice leads to OCD-like behaviour. These mice exhibit increased anxiety and compulsive grooming resulting in facial hair loss and skin lesions. They also have abnormal physiology in the neural circuits involving part of the brain called the striatum.
The authors report that the behavioural symptoms of Sapap3-deficient mice are alleviated by selective serotonin reuptake inhibitors, the class of drugs frequently used to treat OCD in human patients. They also show that both the behavioural and the physiological symptoms are rescued by specific re-introduction of Sapap3 into the striatum. This suggests that this mouse model will provide new means for testing theories of the neurobiological defects and treatment strategies for OCD.
Guoping Feng (Duke University Medical Center, Durham, NC, USA)
Natalie Frazin (NINDS Office of Communications and Public Liaison, NIH, Bethesda, MD, USA)
(C) Nature press release.
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