Reaction of Human Neocortex Astrocytes to Clinical Death and Reperfusion

Abstract

The aimof research was to study the effect of clinical death and reperfusion on astrocytes of the human cerebral cortex.Material and methods.Structural types, quantity, shape, size and distribution of cortical layers I–VI astrocytes (fields 4, 10, 17 and 21) were studied in 7 days after 3-minute clinical death (n=3, males) using a confocal microscope, fluorescence immunohistochemistry (GFAP), classical morphometry and fractal analysis. The control group (n=4, males) included patients died from severe traumatic brain injury.Results.A complex integrated system of GFAP-positive cells consisting of translaminar and intralaminar astrocytes of the fibrous, protoplasmic and mixed types, was revealed in the human cerebral cortex. The bodies of translaminar astrocytes were localized in layers I (had smooth long thin processes) and layers V–VI (had processes with varicose thickening). The processes of translaminar astrocytes penetrated towards each other and intertwined at the level of layer I and II. Qualitative and quantitative changes of all types of intralaminar and translaminar astrocytes were revealed in the human cerebral cortex in 7 days after clinical death. The percentage of the GFAP-positive area increased in all layers of the studied cerebral cortex departments. An increase in GFAP expression in cortical astrocytes was accompanied by changes in the fractal distribution and lacunarity of their processes distribution, the fact supporting a spatial reorganization of the astroglial network in response to acute ischemia and reperfusion of the brain. To a greater extent this related to the processes of fibrous perivascular astrocytes. All these manifestations of reactive astrogliosis might be associated with the activation of adaptivereparative processes in astrocytes. No statistically significant differences between the cerebral cortex fields were revealed.Conclusion.The results obtained showed that clinical death and reperfusion resulted in a structuralfunctional reorganization of the neuroglial network of the cerebral cortex accompanied by an increase in the GFAF expression and complication of the spatial distribution of the processes in all types of astrocytes.