Ultrastructural damage of capillaries in the neocortex in schizophrenia.

Objectives: Neuroimaging studies showed lowered blood flow, glucose metabolic rates and hypoactivation of the prefrontal cortex (PFC) in patients with schizophrenia. The aim of the study was to clear up whether there are abnormalities in the microvasculature in the neocortex in schizophrenia.

Methods: Capillaries were studied in PFC (BA 10) and visual cortex (VC) (BA 17) by electron microscopy and morphometry in 26 schizophrenia cases and 26 normal controls. Capillary diameter and areas of capillaries and of pericapillary astrocytic end-feet were estimated in layers I-II of the prefrontal and visual cortices.

Results: Ultrastructural abnormalities of capillaries in schizophrenia included thickening, deformation of basal lamina, vacuolation of cytoplasm of endothelial cells, basal lamina and astrocytic end-feet, swelling of astrocytic end-feet, of pericapillary oligodendrocytes and signs of activation of microglial cells in both PFC and VC. Capillary diameter and area did not differ significantly between the groups. Area of astrocytic end-feet was significantly higher in PFC (+49%, P<0.001) and in VC (+29%, P<0.01) in schizophrenic group and in different clinical subgroups as compared to controls.

Conclusions: Ultrastructural abnormalities of capillaries and of pericapillary cellular environment found suggest that blood-brain barrier dysfunction might contribute to the pathogenesis of cortical lesions in schizophrenia.