Development of human hypothalamus at the end of the first and in the second trimester of gestation

Abstract

The paper deals with the embryonic development of human hypothalamus at the end of the first and during the second trimesters of gestation. Bearing in mind that the mammal brain, as an entity, develops from the prosencephalic, mesencephalic and rhombencephalic vesicles, which are noticeable in the cranial portion of the neural tube in the 4th week of gestation, and that diencephalon is manifested in the eye vesicle at the same gestational age, authors presented the neuronal secretory activity in that period. The secretory activity of both neurons and hypothalamic nuclei, as well as their maturation, were followed-up by certain immunohistochemical and immunoradiological methods based on structural identification of some factors (primarily protein molecules), which made it possible to determine the specificity of secretory activity of hypothalamic nuclei (ex. tuberohypophyseal pathways), as well as the levels of the hormone release into the hypothalamo-hypophysial complex. The aim of this work was to estimate the catecholamine activity during the development of the respective part of the brain in the 5th, 6th, 11th and 13th week of gestation and later.