Structural and functional transformations of the brain in experimental mild traumatic brain injury

Abstract

In mild traumatic brain injury, it is of interest to study neurode-generative conditions resulting from inflammatory changes in the nervous tissue. Purpose of the study: in the acute period in case of mild experimental traumatic brain injury, to reveal structural transformations of the nervous tissue of the brain. A modified model of a falling weight was used to reproduce of these trauma in adult rats. An immunohistochemical study of the brain with using rat-specific monoclonal antibodies to endothelin-1, glial fibrillar acidic protein, vimentin, and blood-brain barrier endothelial protein (SMI 71) was performed. It has been established that on the first day after injury in the cerebral cortex of animals, the spasm of blood vessels with capillary ischemia predominates. On day 8, there is an increase in the number of hyper- and hypochromic neurons, and after 14 days, restoration of the tone of the microcircu-latory bed is detected with signs of a violation of the permeability of the blood-brain barrier. A significant redistribution in the tissues of the cerebral hemispheres of glial elements containing acid glial protein and vimentin, as well as neurons producing endothelin-1, was noted. In the delayed post-traumatic period, compensatory reactions of the nervous tissue were revealed, which are characterized by the presence of morphological changes in neurons (an increase in the diameter and number of nucleoli in size) associated with intracellular regeneration, as well as the synthesis of various protein factors in them. Thus, the pathogenesis of mild experimental craniocerebral injury in the ischemic (1 day) and intermediate (8 days) periods is characterized by the presence of mild violations of the structural integrity of the nervous tissue of the brain. In the late post-traumatic period (14 days), neurons and astrocytes exhibit compensatory reactions.