Intrinsic functional connectivity alteration of dorsal and rostral anterior cingulate cortex in obsessive-compulsive disorder: A resting fMRI study

Cortico-striato-thalamo-cortical (CSTC) circuit has been implicated in OCD pathophysiology by converging neuroimaging findings. The anterior cingulate cortex (ACC), as an important part within CSTC circuit, plays a critical role in OCD etiology. The ACC can be divided into dorsal and rostral parts anatomically, which are involved in cognitive process and emotional function, respectively. However, the diverse function of intrinsic signals from dorsal and rostral ACC regions remains unclear in OCD study. In this work, we applied resting-state functional magnetic resonance imaging (rs-fMRI) technology to investigate and differentiate the functional connectivity (FC) characteristics between dACC and rACC in unmedicated OCD patients. Also, the correlation between the altered FC and clinical symptom severity was analyzed. Decreased FC of rACC-DLPFC and increased FC between dACC and caudate were found. Moreover, the altered dACC-caudate FC was positively correlated with total Y-BOCS and compulsion score in OCD patients. Our findings implied the crossed function of dorsal and rostral circuits in the pathophysiologic mechanism of OCD. The dorsal cingulate-striatum functional pathway served as a potential biomarker for OCD symptomatology and merits further investigations.