A common molecular mechanism for cognitive deficits and craving in alcoholism

Alcohol-dependent patients commonly show impairments in executive functions that facilitate craving and can lead to relapse. The medial prefrontal cortex, a key brain region for executive control, is prone to alcohol-induced neuroadaptations. However, the molecular mechanisms leading to executive dysfunction in alcoholism are poorly understood. Here using a bi-directional neuromodulation approach we demonstrate a causal link for reduced prefrontal mGluR2 function and both impaired executive control and alcohol craving. By neuron-specific prefrontal knockdown of mGluR2 in rats, we generated a phenotype of reduced cognitive flexibility and excessive alcohol-seeking. Conversely, restoring prefrontal mGluR2 levels in alcohol-dependent rats rescued these pathological behaviors. Also targeting mGluR2 pharmacologically reduced relapse behavior. Finally, we developed a FDG-PET biomarker to identify those individuals that respond to mGluR2-based interventions. In conclusion, we identified a common molecular pathological mechanism for both executive dysfunction and alcohol craving, and provide a personalized mGluR2-mechanism-based intervention strategy for medication development of alcoholism.