Tadtayev S. Stereological investigation of specific brain regions in a developmental model of chronic intermittent hypoxia

Object of the study: pathological anatomy of the brain under influence of chronic intermittent hypoxia. Aim of the study: to establish morphological changes in the cortex, hippocampus, nucleus of hypoglossal nerve and ambigual nucleus during early postnatal development in experimental model of chronic intermittent hypoxia (CIH). Methods of the study: macroscopic, stereological, histological, histochemical, immunohistochemical, statistical. Practical significance of the obtained results: completed investigation of the morphology of the cortex, hippocampus, hypoglossal nucleus and nucleus ambiguus gave an opportunity to observe and detect changes in the development of these structures under influence of CIH. The detected changes and observed correlations shed light on aspects of the CIH pathology and allow extrapolations to cognitive and behavioural impairments characteristic of pediatric obstructive sleep apnoea to be made. Scientific novelty of the obtained results: for the first time it was possible to establish morphological changes in the cortex, hippocampus, hypoglossal nucleus and nucleus ambiguus of Sprague-Dawley rats during early postnatal development in the experimental rodent model of chronic intermittent hypoxia. Results of the study expand current knowledge about the role and importance of chronic intermittent hypoxia in pathogenesis and morphogenesis of obstructive sleep apnoea. Research clarifies pathogenesis of the changes in the neural substrates that lead to cognitive and behavioural changes characteristic of chronic intermittent hypoxia influence. It was shown that chronic intermittent hypoxia causes a number of pathological changes: decrease in a number of neurons and glial cells, astrogliosis in pyramidal layer of the CA1 hippocampal field, decrease in the nuclear volume of the hypoglossal neurons, gender-related disbalance in the number of glial cells and increase in number of neurons in the cortex of the experimental animals. Author established character, direction and cause-effect relations of the observed morphological changes and cognitive, behavioural impairment and disfunction of upper airway motor control in animals subjected to chronic intermittent hypoxia. Furthermore, assessment of the capacity for morphological recovery following completion of the experimental protocol was completed, as well as extrapolation of the experimental data on consequences of obstructive sleep apnoea in children. Introduction: The results of the study were introduced into the teaching process in the departments of pathological anatomy; histology, cytology and embryology; pathological physiology of Kharkov state medical university, department of pathological anatomy of Kharkov state university (Karazin), department of pathological anatomy of Kharkov medical academy of post-graduate education. Sphere of application: medicine, pathological anatomy