GRIA4 and autosomal dominant cerebellar ataxia: Furthermore, in line with our microarray results, glutamate treatment further reduced the expression of glutamate receptor-related genes, including GRIA1, GRIA2, GRIA4, GRM3 and SLC17A6, in the SCA-iPSC-derived neurons compared to their counterparts derived from CTRL-iPSCs (Fig. 4Ab).