A study that used a rotarod and rod tests to assess the motor performance of mice with rotenone-induced PD showed that piperine treatment attenuated the rotenone-induced motor deficits and rescued nigrostriatal DA loss by inhibiting the activation of autophagy through the protein phosphatase 2A (PP2A)-mediated inhibition of AKT–mTORC1 signaling, which, in turn, protected SK-N-SH cells and primary neurons from mitochondrial damage induced by rotenone treatment [23]. This evidence concerns the gene AKT1 and Parkinson disease.