Bipolar disorder type 1 and schizophrenia are accompanied by decreased density of parvalbumin- and somatostatin-positive interneurons in the parahippocampal region

• Published in: Acta neuropathologica Vol. 122; no. 5; pp. 615 - 626
• Main Authors: Wang, Alice Y., Lohmann, Kathryn M., Yang, C. Kevin, Zimmerman, Eric I., Pantazopoulos, Harry, Herring, Nicole, Berretta, Sabina, Heckers, Stephan, Konradi, Christine
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.11.2011; Springer Nature B.V
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Autopsy; Bipolar disorder; Bipolar Disorder - metabolism; Bipolar Disorder - pathology; Brain; Calbindins; Case-Control Studies; Cell Count; Circuits; Cortex (entorhinal); Cortex (subicular); Entorhinal Cortex - metabolism; Entorhinal Cortex - pathology; Female; gamma -Aminobutyric acid; Hippocampus; Hippocampus - metabolism; Hippocampus - pathology; Humans; Information processing; Integration; Interneurons; Interneurons - metabolism; Interneurons - pathology; Male; Medical records; Medicine; Medicine & Public Health; Mental disorders; Middle Aged; Nerve Net - metabolism; Nerve Net - pathology; Neurons; Neurosciences; Original Paper; Parahippocampal Gyrus - metabolism; Parahippocampal Gyrus - pathology; Parvalbumins - metabolism; Pathology; S100 Calcium Binding Protein G - metabolism; Schizophrenia; Schizophrenia - metabolism; Schizophrenia - pathology; Somatostatin - metabolism; Stains & staining; Synchronization; Young Adult; United States > US; Nashville Tennessee; Interneurons; Entorhinal cortex; Schizophrenia; Bipolar disorder; Subiculum; Somatostatin; Parahippocampal gyrus; Parvalbumin
• ISSN: 0001-6322; 1432-0533; 1432-0533
• DOI: 10.1007/s00401-011-0881-4

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.