Interestingly, proinflammatory cytokines like interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) downregulated the expression of mGluR5 while upregulating that of mGluR3 in cortical astrocytes isolated from the hSOD1(G93A) rat model of amyotrophic lateral sclerosis (entailing like AD an intense neuroinflammation) and cultured in vitro. Here, GRM5 is linked to Alzheimer disease.