After the induction of PD (with LPS), the model showed an increased regulation of proinflammatory mediators (TNF-α, IL-1 and IL-6), the loss of dopaminergic neurons, a reduction in mGluR5+ microglial cells, an increase in TSPO+ microglial cells, a reduction in H3K9 acetylation in the mGluR5 promoter region, and mGluR5 mRNA reduction with a decrease in the phosphorylation levels of the Akt/GSK-3/CREB pathway. Here, GRM5 is linked to Parkinson disease.