title: Bipolar disorder type 1 and schizophrenia are accompanied by decreased density of parvalbumin- and somatostatin-positive interneurons in the parahippocampal region.
abstract: GABAergic interneurons synchronize network activities and monitor information flow. Post-mortem studies have reported decreased densities of cortical interneurons in schizophrenia (SZ) and bipolar disorder (BPD). The entorhinal cortex (EC) and the adjacent subicular regions are a hub for integration of hippocampal and cortical information, a process that is disrupted in SZ. Here we contrast and compare the density of interneuron populations in the caudal EC and subicular regions in BPD type I (BPD-I), SZ, and normal control (NC) subjects. Post-mortem human parahippocampal specimens of 13 BPD-I, 11 SZ and 17 NC subjects were used to examine the numerical density of parvalbumin-, somatostatin- or calbindin-positive interneurons. We observed a reduction in the numerical density of parvalbumin- and somatostatin-positive interneurons in the caudal EC and parasubiculum in BPD-I and SZ, but no change in the subiculum. Calbindin-positive interneuron densities were normal in all brain areas examined. The profile of decreased density was strikingly similar in BPD-I and SZ. Our results demonstrate a specific reduction of parvalbumin- and somatostatin-positive interneurons in the parahippocampal region in BPD-I and SZ, likely disrupting synchronization and integration of cortico-hippocampal circuits.
authors.affiliation: Neuroscience Program for Undergraduates, Vanderbilt University, Nashville, TN, USA.
authors.forename: Alice Y
authors.initials: AY
authors.lastname: Wang
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Lohmann
authors.forename: C Kevin
authors.initials: CK
authors.lastname: Yang
authors.forename: Eric I
authors.initials: EI
authors.lastname: Zimmerman
authors.forename: Harry
authors.initials: H
authors.lastname: Pantazopoulos
authors.forename: Nicole
authors.initials: N
authors.lastname: Herring
authors.forename: Sabina
authors.initials: S
authors.lastname: Berretta
authors.forename: Stephan
authors.initials: S
authors.lastname: Heckers
authors.forename: Christine
authors.initials: C
authors.lastname: Konradi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001344:Autopsy; D001714:Bipolar Disorder / Q000378:metabolism / Q000473:pathology*; D064026:Calbindins; D016022:Case-Control Studies; D002452:Cell Count; D018728:Entorhinal Cortex / Q000378:metabolism / Q000473:pathology; D005260:Female; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007395:Interneurons / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000378:metabolism / Q000473:pathology; D020534:Parahippocampal Gyrus / Q000378:metabolism / Q000473:pathology*; D010320:Parvalbumins / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000378:metabolism; D012559:Schizophrenia / Q000378:metabolism / Q000473:pathology*; D013004:Somatostatin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D064026:Calbindins; D010320:Parvalbumins; D064030:S100 Calcium Binding Protein G; D013004:Somatostatin