The morphological and functional state of the arcuate nucleus of the hypothalamus of rats in burn injury dynamics

Morphological and morphometric features of cells of arcuate nucleus of hypothalamus in dynamics of thermal burn trauma of skin are considered. The relevance of the study is due to the important role of reactive changes in the neuroendocrine regulatory complex in the pathogenesis of skin burn wounds. Since the hypothalamus is part of neuroendocrine cooperation, it shows the most pronounced signs of neuronal damage. In this regard, the aim of the study was to study qualitative and quantitative structural changes in the arcuate nucleus of the middle hypothalamus of rats in the simulation of thermal burn injury to the skin. Burn exposure was simulated in male nonlinear rats weighing 200-230 g by applying contact thermal trauma in the interblade region of the back. The functional activity of the arcuate nucleus of the hypothalamus was evaluated by quantitative analysis of the morphometric parameters of neurocyte nuclei because these organoids correlate with transcription intensity and can serve as a tool for assessing their functional state. To carry out quantitative analysis of histological preparations of hypothalamus, planimetric properties of neurons and their structures were determined: absolute values of neurons, such as: area of pericaryons, area of neurons nuclei, area of cytoplasm of neurons, nuclear-cytoplasmic ratio of neurons of arcuate nuclei of hypothalamus. On the basis of the obtained data on absolute values of neurons relative values were calculated - median area of pericaryons, median area of nuclei, median area of cytoplasm of pericaryons, median of nuclear-cytoplasmic ratio of neurons of arcuate nuclei of hypothalamus. The study revealed destructive transformations of this hypothalamic brain zone in all stages of inflammatory-regenerative reaction: on 2, 4, 7, 10 days after burn exposure. Comparative analysis of hypothalamus preparations of laboratory animals showed characteristic destructive changes in arcuate nuclei in conditions of thermal skin injury, which reflected the development of processes of reversible and irreversible damage to neurons. The detected features are generally consistent with existing ideas about the disruption of morphofunctional organization of neurons in this zone due to the implementation of adaptive mechanisms characterized by activation of local and systemic compensatory-restorative processes, focal gliosis and development of edema changes of nerve cells.