title: Evidence for altered neuronal organisation within the planum temporale in major psychiatric disorders.
abstract: Reductions in neuronal size and glial cell density have been described in the frontal cortex in major psychiatric disorders. In this investigation, we performed a cytoarchitectural assessment within the planum temporale (PT), an auditory association region located within the superior temporal gyrus, using two-dimensional (2D) measures of cell size and density and spatial point pattern analysis. In sections of the PT from subjects with schizophrenia, bipolar disorder, major depressive disorder and controls (15 subjects per group), the laminar distribution and size of all neurons and glial cell nuclei was recorded. Spatial point pattern investigation demonstrated reduced neuronal clustering in bipolar disorder (p=0.033) and schizophrenia (p=0.027) compared with controls. Statistical analyses comparing each of the patient groups with the control group failed to identify differences in neuronal density between groups. Neuronal size was reduced in cortical layer 3 (p=0.02) and glial cell density reduced in cortical layer 6 (p=0.05) in bipolar disorder relative to controls but these findings did not remain significant after adjusting for six layer-wise comparisons. We propose that alterations in cortical cytoarchitecture within this region are subtle and involve reduced clustering of neurons, which may be due to altered neuronal organisation within cortical mini-columns or within cortical layers.
authors.affiliation: Department of Neuropathology, Institute of Psychiatry, DeCrespigny Park, London SE5 8AF, UK. cbeasley@interchange.ubc.ca
authors.forename: Clare L
authors.initials: CL
authors.lastname: Beasley
authors.forename: Gursharan
authors.initials: G
authors.lastname: Chana
authors.forename: Mrinalini
authors.initials: M
authors.lastname: Honavar
authors.forename: Sabine
authors.initials: S
authors.lastname: Landau
authors.forename: Ian P
authors.initials: IP
authors.lastname: Everall
authors.forename: David
authors.initials: D
authors.lastname: Cotter
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000473:pathology* / Q000503:physiopathology; D002452:Cell Count; D003865:Major Depressive Disorder / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000473:pathology* / Q000503:physiopathology; D009457:Neuroglia / Q000502:physiology; D009474:Neurons / Q000502:physiology; D010784:Photomicrography; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology