Deficit of pericapillary oligodendrocytes in the prefrontal cortex in schizophrenia

Objective: Our previous studies have shown a significant decrease of numerical density of oligodendrocytes in the prefrontal cortex in postmortem schizophrenic brains. Deficit of oligodendrocytes was associated with loss of oligodendroglial satellites of pyramidal neurons. In this study we tested the hypothesis that there might be a deficit and loss of pericapillary oligodendrocytes in the prefrontal cortex in schizophrenia. Method: Autopsy samples from the prefrontal cortex (BA 10) were obtained from 12 normal controls and 12 chronic schizophrenic cases. Capillaries and oligodendrocytes were viewed in paraffin sections stained with a Luxol-fast blue and cresyl violet. Electron microscopy was applied to study the ultrastructure of oligodendrocytes. For morphometric analysis, an average of 100 rectilinear capillary segments from layer V was sampled for each individual. The number of oligodendrocytes visible along rectilinear segments was expressed as the number of oligodendrocytes per 0.01 mm of capillary length. Results: Subjects with schizophrenia had a significantly lower (-23%; P0.005) number of pericapillary oligodendrocytes compared to controls. Prominent ultrastructural dystrophic and degenerative alterations of pericapillary oligodendrocytes have been revealed in schizophrenic brains. Conclusion: The present study provides evidence that there is a prominent reduction, damage and loss of pericapillary oligodendrocytes in the prefrontal cortex in schizophrenia. These changes may contribute to the pathophysiological basis for altered blood-brain barrier and lowered metabolic rates in subjects with schizophrenia.