DRD2 and Parkinson disease: In MPTP-induced PD mice and human microglia, dopamine inhibits the activation of microglial NLRP3 inflammasome through signaling via DRD1 and DRD2, leading to the ubiquitination and subsequent degradation of NLRP3.224 Similarly, inhibiting microglial NLRP3 inflammasome activation significantly reduced dopaminergic neurodegeneration and ameliorated motor deficits in the MPTP-treated mice, although the mechanism behind this remains unknown.225 Neuronal NLRP3 has also been implicated in PD pathogenesis.