Development of molecular tools based on the dopamine D3 receptor ligand FAUC 329 showing inhibiting effects on drug and food maintained behavior.

Dopamine D3 receptor-mediated networks have been associated with a wide range of neuropsychiatric diseases, drug addiction and food maintained behavior, which makes D3 a highly promising biological target. The previously described dopamine D3 receptor ligand FAUC 329 (1) showed protective effects against dopamine depletion in a MPTP mouse model of Parkinson's disease. We used the radioligand [18F]2, a [18F]fluoroethoxy substituted analog of the lead compound 1 as a molecular tool for visualization of D3-rich brain regions including the islands of Calleja. Furthermore, structural modifications are reported leading to the pyrimidylpiperazine derivatives 3 and 9 displaying superior subtype selectivity and preference over serotonergic receptors. Evaluation of the lead compound 1 on cocaine-seeking behavior in non-human primates showed a substantial reduction in cocaine self-administration behavior and food intake.