THE FORMATION OF THE HYPOTHALAMIC-NEUROHYPOPHYSIAL SYSTEM IN THE EARLY PERIOD OF POSTNATAL ONTOGENESIS

Authors:

Abstract:

Research devoted to the study of morpho-functional organization pituitary-neurohypophysial system in the early period of postnatal ontogenesis. The survey used the hypothalamus and neurohypophysis of 30 rats Wistar males aged 1, 15 and 30 days. Used histological and electronnomicroscopic methods. Found that in infant’s rats in young neurons of supraoptic and paraventricular nuclei existing isolated immature neurosecretory granules that are found in axons of neurohypophysis. Glial cells undifferentiated, and only unmyelinated nervous fibers are in the neuropole, axo-somatic and axo-dendritic synapses. Blood-brain barrier is not formed and characterized by direct contact of neurons and capillaries. Neurohypophysis consists of small terminal branches of axons, which mainly contain synaptic vesicles, surrounded on all sides by pituicytes, single axo-vasal synapses. With increasing period of postnatal ontogenesis neurons differentiated into light and dark neurosecretory cells that contain well-developed protein-synthesizing apparatus and neurosecretory mature granules. Among glial cells allocated protoplasmic and fibrous astrocytes, oligodendrogliocytes and microglial cells. In neuropole appear myelinated nervous fibers. Continued formation of blood-brain barrier, which formed from capillary wall and processes of glial cells. In neurohypophysis increasing number of axo-vasal synapses, appear Herring cells. In the terminal endings of axons localizing young, mature and diffusing neurosecretory granules.

Keywords:

supraoptical nucleus paraventricular nucleus neurohypophysis ontogenesis

References:

1. Алешин Б. В. Гистофизиология гипоталамо-гипофизарной системы / Алешин Б. В. – М.: Медицина, 1971. – 439 с.
2. Бабийчук В. Г. Структурно-функциональное состояние гематоэнцефали­чес­кого барьера гипоталамуса старых крыс при действии экстремального охлаждения / В. Г. Бабийчук, В. С. Марченко // Світ медицини та біології. – 2005. - № 3. – С. 91-94.
3. Войткевич А. А. Ультраструктурне основы гипоталамической нейросекреции / А. А. Войткевич, И. И. Дедов. – М.: Медицина, 1972. – 240 с.
4. Becquet D. Ultrastructural plasticity in the rat suprachiasmatic nucleus. Possible involvement in clock entrainment / D. Becquet, C. Girardet, F. Guillaumond // Glia. – 2008. – V. 56, № 3. – P. 294-305.
5. Belenky M. A. Heterogeneous expression of gamma-aminobutyric acid and gamma-aminobutyric acid-associated receptors and transporters in the rat suprachiasmatic nucleus / M. A. Belenky, Y. Yarom, G. E. Pickard // J. Comp. Neurol. – 2008. - V. 506, № 4. – P. 708-732.
6. Hyodo S., Yamada C, Takezava Т., Urano A. Expressions of pro vassopressin gene during ontogeny in the hypothalamus of developing mice // Neuroscience. -1992.-Vol.46.-P.241-250.
7. Villagra N.T. Nuclear compartmentalization and dynamics of the poly(A)-binding protein nuclear 1 (PABPN1) inclusions in supraoptic neurons under physiological and osmotic stress conditions // N.T. Villagra, R.Bengoechea, J.Llorca [et al.] // Mol. Cell. Neurosci. – 2008. – V.37, №3. – P.622-633

Publication:

«World of Medicine and Biology» Vol. 8 No. 33 (2012) , с. 98-103
УДК 611.814.1 + 611.814.3