GRM2 and major depressive disorder: Furthermore, in light of evidence suggesting that the neurobiological underpinnings of cognitive functions share both overlapping and discrete features with those subserving mood regulation, translational avenues of research are broadening the range of possible pharmacological novel targets relevant to cognitive dysfunction in MDD, including membrane receptors (e.g. metabotropic glutamate receptor 2/3 antagonists) and intracellular pathways, such as protein kinases, phosphodiesterases, and epigenetic modifications [85, 184].