Imaging extra-striatal dopamine D2 receptors in a maternal immune activation rat model

Maternal immune activation (MIA) is a risk factor for schizophrenia in the offspring. MIA in pregnant rodents canbe induced by injection of synthetic polyriboinosinic-polyribocytidilic acid (Poly I:C), which causes decreasedstriatal dopamine D2 receptor (D2R) expression and behavioral dysfunction mediated by the dopaminergic systemin the offspring. However, previous studies did not determine whether Poly I:C induced cortical dopamine D2Rabnormality in an MIA rat model. In this study, we performed micro-positron emission tomography (micro-PET) invivo imaging and ex vivo neurochemical analyses of cortical D2Rs in MIA. In the micro-PET analyses, the anteriorcingulate cortex (ACC) region in the offspring showed significantly reduced binding potential for [11C]FLB457, ahigh affinity radio-ligand toward D2Rs. Neurochemical analysis showed reduction of D2Rs and augmentation ofdopamine turnover in the ACC of the rat offspring. Thus, MIA induces dopaminergic dysfunction in the ACC ofoffspring, similar to the neuronal pathology reported in patients with schizophrenia