Формирование транзиторных зон в дорсомедиальной и дорсолатеральной неокортикальных областях в раннем развитии человека

Abstract

Introduction. Transient zones form during prenatal corticogenesis and disappear and are replaced by mature white and gray matter in postnatal ontogenesis. The growth trajectories of transient zones have not been completely characterized, and quantitative data describing these processes are still scarce. We aimed to describe the hemispheric wall stratification during 3–4 months of intrauterine development and clarify timing of major transient zone formation in dorsolateral and dorsomedial neocortical areas.Materials and methods. We examined 12 autopsy brain samples of human fetuses at postcoital weeks 8–15. Nissl, Mallory trichrome, and haematoxylin and eosin histological preparations were analyzed. Then we performed morphometric and statistical analyses.Results. Consecutive formation and growth of transient zones in hemispheric walls occur during early prenatal development at postcoital weeks 8–15. Nissl, Mallory trichrome, and haematoxylin and eosin histological preparations were analyzed. In the dorsomedial hemispheric wall, the development of transient zones is delayed compared to that in the dorsolateral one.Conclusion.The formation of transient zones in dorsomedial and dorsolateral hemispheric walls is characterized by regional heterochrony, which could account for neocortical area differentiation and needs further research. Keywords: transient zones, neocortex, neurogenesis, corticogenesis, human prenatal development