Ultrastructural pathology of oligodendrocytes in white matter in continuous attack-like schizophrenia and a role for microglia

Abstract

Previously the authors have reported the ultrastructural pathology and deficits of oligodendrocytes in gray and white matter of the prefrontal cortex in continuous paranoid schizophrenia. The aim of the present work was to study the effects of microglia on the ultrastructure of oligodendrocytes in white matter underlying the prefrontal cortex (BA10) in attack-like schizophrenia. Postmortem morphometric electron microscopic study of oligodendrocytes in close apposition to microglia was performed in white matter underlying the prefrontal cortex (BA10). Nine cases of chronic attack-like schizophrenia and 20 normal controls were studied. Areas of oligodendrocytes, volume density (Vv) and the number of mitochondria, vacuoles of endoplasmic reticulum and lipofuscin granules were estimated. Group comparison was performed using ANCOVA. The schizophrenia group differed from the control group by paucity of ribosomes in cytoplasm of oligodendrocytes, cytoplasm swelling, a significant increase in Vv and number of vacuoles and lipofuscin granules. Significant correlations between the parameters of vacuoles and lipofuscin granules and mitochondria were found only in the schizophrenia group. Dystrophic alterations of oligodendrocytes apposed microglial cells were found in the white matter of the prefrontal cortex in chronic schizophrenia as compared to controls. Microglia might contribute to abnormalities of lipid and protein metabolism of oligodendrocytes.