Histoarchitectonically distinct regions of anterior cingulate show altered glutamatergic metabolism in major depressive disorder

Increasing evidence suggests a hypoglutamatergic state in major depressive disorder (MDD), however spatial- and metabolite specific abnormalities have not been fully characterized. Using short TE/TM STEAM MRS, we evaluated Glu, Gln, Gln/Glu and GABA metabolism in two histoarchitectonically distinct subdivisions of the anterior cingulate cortex (ACC). The pregenual ACC, involved in emotion processing, showed altered glutamine-glutamine cycling but not altered GABAergic metabolism in MDD, whereas no differences between patients and controls were found in the anteromedial ACC. Increased Gln/Glu in MDD in pgACC but not aMCC confirms a regionally specific role of altered glutamatergic metabolism and neuronal-glial interaction