title: Laminar and cellular analyses of reduced somatostatin gene expression in the subgenual anterior cingulate cortex in major depression.
abstract: Somatostatin (SST), a neuropeptide expressed in dendritic-targeting gamma-aminobutyric acid (GABA) neurons, is decreased across corticolimbic areas in major depressive disorder (MDD). SST-positive GABA neurons form heterogeneous subgroups with different laminar distributions and electrophysiological properties, so knowing the anatomical and cellular localization of reduced SST may provide insight into the nature of the pathology in MDD. In cohorts of MDD subjects with known reduction of SST in postmortem sgACC gray matter, we used in situ hybridization to quantify the laminar and cellular patterns of altered SST mRNA expression. SST mRNA levels were lower across all cortical layers in the MDD subjects. Expression levels per cell were also lower, but the density of labeled neurons did not differ between subject groups. Consistent with the previous tissue level analysis, differences were more robust in females. In summary, we report MDD-related reduction in SST expression per cell across cortical layers in sgACC, suggesting a general vulnerability of SST neurons independent of specific cell type.
authors.affiliation: Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Marianne L
authors.initials: ML
authors.lastname: Seney
authors.affiliation: Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Tripp
authors.affiliation: Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: McCune
authors.affiliation: Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Lewis
authors.affiliation: Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA; Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA; Campbell Family Research Institute, Centre for Addiction and Mental Health, Departments of Psychiatry, Pharmacology and Toxicology, University of Toronto, Toronto, Canada. Electronic address: etienne.sibille@camh.ca.
authors.forename: Etienne
authors.initials: E
authors.lastname: Sibille
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001344:Autopsy; D003865:Major Depressive Disorder / Q000378:metabolism*; D005260:Female; D059330:GABAergic Neurons / Q000378:metabolism*; D015870:Gene Expression; D006179:Gyrus Cinguli / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000378:metabolism; D012737:Sex Factors; D013004:Somatostatin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D012333:RNA, Messenger; D013004:Somatostatin
keywords: Anterior cingulate cortex; Depression; Postmortem; Somatostatin