Current information about morphogenesis of pons in the prenatal period of human ontogenesis

Abstract

Investigation of intrauterine development mechanisms of the CNS becomes relevant because of the high prevalence of congenital malformations of the nervous system. Every year the number of patients with congenital defects of the nervous system increases, which, on the one hand, can be attributed to the improvement of postnatal neuroimaging techniques, and on the other hand, a significant increase in the influence of adverse factors on the development of the brain in the prenatal period of ontogenesis. Congenital malformations of the CNS account for about 25% of all children birth defects, and their part in the structure of perinatal and infant mortality is currently about 30%. Nowadays in Ukraine, there is no accurate data on the prevalence of congenital malformations of the CNS with the release of certain nosological forms. The analysis of scientific literature, which highlights the state of studies related to macro-, morphogenesis, histogenesis and topography of bridge structures in the prenatal period of human ontogenesis, was conducted. It is revealed that in the scientific literature there is insufficient data on the chronological sequence of macrometric and morphological changes during the formation of human pons nuclei at the prenatal period of ontogenesis. Despite the significant role of the pons in the implementation of global brain functions, its prenatal development remains insufficiently investigated. Knowledge of the migration mechanisms and differentiation of the pons nuclei neurons will allow to understand better the molecular and cellular basis of the formation and functioning of the cortico-cerebellar leading way. The cranial nerves nuclei which are contained in the pons play an important role in the formation of early postnatal reflexes, as well as in the realization of brain sensory functions. Most researches on the embryonic development of the pons are conducted on experimental animals, which cannot always be extrapolated to humans. Besides there are no works of complex immunohistochemical research on the development and formation of pons nuclei in the prenatal period of human ontogenesis. All the above provides wide opportunities for further study of this issue.