Dionyssios Mintzopoulos1, Timothy E. Gillis1, Holly R. Robertson2, Guoping Feng2, Scott L. Rauch1, Marc J. Kaufman1
1McLean Hospital, Harvard Medical School, Belmont, MA, United States; 2Dept. of Brain and Cognitive Sciences, MIT McGovern Institute for Brain Research, Cambridge, MA, United States
Obsessive compulsive disorder (OCD) lifetime prevalence is ~2% yet OCD etiology is poorly understood. The SAPAP3 knockout mouse was developed as a model of OCD. Knockout mice have striatal abnormalities and exhibit compulsive grooming behavior leading to skin lesions. We used 9.4T MRI to quantify ventricular and total brain volumes (TBV) in knockout mice. TBV was normal but ventricular volumes averaged >50% larger in knockout mice, and in most cases enlargement preceded lesion development, suggesting that brain changes occur before the behavioral phenotype becomes severe. Thus, the SAPAP3 knockout model may help elucidate neurodevelopmental phenomena leading to compulsive behaviors.