TY - JOUR T1 - Metabotropic glutamate receptor mGluR2/3 and mGluR5 binding in the anterior cingulate cortex in psychotic and nonpsychotic depression, bipolar disorder and schizophrenia: implications for novel mGluR-based therapeutics JF - Journal of Psychiatry and Neuroscience JO - J Psychiatry Neurosci SP - 407 LP - 416 DO - 10.1503/jpn.130242 VL - 39 IS - 6 AU - Natalie Matosin AU - Francesca Fernandez-Enright AU - Elisabeth Frank AU - Chao Deng AU - Jenny Wong AU - Xu-Feng Huang AU - Kelly A. Newell Y1 - 2014/11/01 UR - http://jpn.ca/content/39/6/407.abstract N2 - Background: Metabotropic glutamate receptors 2/3 (mGluR2/3) and 5 (mGluR5) are novel therapeutic targets for major depression (MD), bipolar disorder (BD) and schizophrenia. We aimed to determine whether mGluR2/3 and mGluR5 binding in the anterior cingulate cortex (ACC), a brain region essential for the regulation of mood, cognition and emotion, were differentially altered in these pathologies.Methods: Using postmortem human brains derived from 2 cohorts, [3H]LY341495 binding to mGluR2/3 and [3H]MPEP binding to mGluR5 were measured by receptor autoradiography in the ACC. The first cohort comprised samples from individuals who had MD with psychosis (MDP), MD without psychosis (MDNP) and matched controls (n = 11–12 per group). The second cohort comprised samples from individuals who had MDNP, BD, schizophrenia and matched controls (n = 15 per group).Results: No differences in mGluR2/3 or mGluR5 binding were observed in the MDP, MDNP, BD or schizophrenia groups compared with the control group (all p > 0.05). Importantly, there were also no differences in binding densities between the psychiatric disorders (p > 0.05). We did, however, observe age-related effects, with consistent negative associations between mGluR2/3 and age in the control group (r < −0.575, p < 0.025) and the psychotic disorder groups (MDP and schizophrenia: r = −0.765 to −0.515, p < 0.05), but not in the mood disorder groups (MDNP, BD).Limitations: Replication in larger independent cohorts and medication-naive individuals would strengthen these findings.Conclusion: Our findings suggest that mGluRs are unaltered in the ACC; however, the presence of altered receptor function cannot be discounted and requires further investigation. Taken together with previous studies, which report differential changes in mGluR2, 3 and 5 across these disorders, we suggest mGluRs may be affected in a brain region–specific manner. ER -