GRIN2D and major depressive disorder: For instance, the team lead by Duman found no significant difference of GluN1, GluN2A, GluN2B, GluN2C and GluN2D mRNA expression in dentate gyrus (DG) and CA1 subfield of hippocampus between subjects diagnosed with MDD compared to healthy subjects matched for sex and ages [12], while other researchers found the reduced levels of GluN2A and GluN2B subunits in the anterior prefrontal cortex (PFC) [13] and the elevated levels of the GluN2C subunit in the locus coeruleus [14] in depression subjects.