This study is the first to demonstrate that CdCl2-induced toxicity is associated with downregulating the transcription and nuclear activity of PPARγ’s in the hippocampus, consistent with previous reports showing depletion of PPARγ in the cortices and hippocampi of various animal models of neurodegeneration, including ischemia, AD, PD, diabetes mellitus, and ALS [7,53,54,55,56,57]. This evidence concerns the gene PPARG and Parkinson disease.