Small neurosecretory cells ( English parvocellular cells ) are relatively small neurons located in several nuclei of the hypothalamus and forming a small cell neurosecretory system that regulates the release of hormones by the anterior pituitary gland [1] . These cells are most found in the paraventricular and nuclei of the hypothalamus.
Axons of small neurosecretory cells of the paraventricular and arcuate nucleus are projected onto a median elevation in the region of the gray tubercle and secrete peptides into the capillary network of the hypothalamic-pituitary system . In the area of these capillaries, the blood-brain barrier has increased permeability, and hormones and metabolites from the blood can reach the hypothalamic cells and modulate their secretion. Through the short and long veins of the portal system, peptides enter the diffuse capillary network of the anterior pituitary gland, where they inhibit or stimulate the secretion of hormones by target cells [2] [3] .
Cell Types
Different types of small neurosecretory cells in mammals secrete the following peptides:
- Corticotropin-releasing hormone (CRH), which serves as the main regulator of the release of adrenocorticotropic hormone released, for example, in the case of a systemic response to stress [4] [5]
- Thyrotropin -releasing hormone (TRH), which serves as the main regulator of the release of thyroid-stimulating hormone and further regulates the release of prolactin [6]
- Vasopressin , which serves as a secondary regulator of the release of adrenocorticotropic hormone, acting in conjunction with corticoliberin, and also regulates the release of prolactin [5] [7] [8]
- Oxytocin , which regulates the release of prolactin [7] [8] [9]
- Neurotensin , which serves as a regulator of the release of luteinizing hormone and prolactin [5] [10] .
Many neuropeptides and hormones homologous to the hypothalamic and pituitary hormones of mammals are also found in reptiles and birds. This indicates that the small cell neurosecretory system appeared in evolution already in the common ancestor of amniots [1] .
See also
- Large neurosecretory cells
Notes
- ↑ 1 2 Encyclopedia of Neuroscience / Binder MD, Hirokawa N. Windhorst U. (ed.) .. - Springer, 2009 .-- P. 1366. - 4398 p. - ISBN 978-3-540-23735-8 .
- ↑ Sawchenko PE Evidence for differential regulation of corticotropin-releasing factor and vasopressin immunoreactivities in parvocellular neurosecretory and autonomic-related projections of the paraventricular nucleus. (English) // Brain research. - 1987. - Vol. 437, no. 2 . - P. 253-263. - PMID 3325130 .
- ↑ Kovács KJ , Sawchenko PE Sequence of stress-induced alterations in indices of synaptic and transcriptional activation in parvocellular neurosecretory neurons. (English) // The Journal of neuroscience: the official journal of the Society for Neuroscience. - 1996. - Vol. 16, no. 1 . - P. 262-273. - PMID 8613792 .
- ↑ Lennard DE , Eckert WA , Merchenthaler I. Corticotropin-releasing hormone neurons in the paraventricular nucleus project to the external zone of the median eminence: a study combining retrograde labeling with immunocytochemistry. (English) // Journal of neuroendocrinology. - 1993. - Vol. 5, no. 2 . - P. 175-181. - PMID 8485552 .
- ↑ 1 2 3 Sawchenko PE , Swanson LW , Vale WW Co-expression of corticotropin-releasing factor and vasopressin immunoreactivity in parvocellular neurosecretory neurons of the adrenalectomized rat. (Eng.) // Proceedings of the National Academy of Sciences of the United States of America. - 1984. - Vol. 81, no. 6 . - P. 1883-1887. - PMID 6369332 .
- ↑ Ghamari-Langroudi M. , Vella KR , Srisai D. , Sugrue ML , Hollenberg AN , Cone RD Regulation of thyrotropin-releasing hormone-expressing neurons in paraventricular nucleus of the hypothalamus by signals of adiposity. (English) // Molecular endocrinology (Baltimore, Md.). - 2010 .-- Vol. 24, no. 12 . - P. 2366-2381. - DOI : 10.1210 / me.2010-0203 . - PMID 20943814 .
- ↑ 1 2 Horn AM , Robinson IC , Fink G. Oxytocin and vasopressin in rat hypophysial portal blood: experimental studies in normal and Brattleboro rats. (English) // The Journal of endocrinology. - 1985. - Vol. 104, no. 2 . - P. 211-224. - PMID 3968510 .
- ↑ 1 2 Freeman ME , Kanyicska B. , Lerant A. , Nagy G. Prolactin: structure, function, and regulation of secretion. (English) // Physiological reviews. - 2000. - Vol. 80, no. 4 . - P. 1523-1631. - PMID 11015620 .
- ↑ Johnston CA , Negro-Vilar A. Role of oxytocin on prolactin secretion during proestrus and in different physiological or pharmacological paradigms. (English) // Endocrinology. - 1988. - Vol. 122, no. 1 . - P. 341-350. - DOI : 10.1210 / endo-122-1-341 . - PMID 3335212 .
- ↑ Watanobe H. , Takebe K. In vivo release of neurotensin from the median eminence of ovariectomized estrogen-primed rats as estimated by push-pull perfusion: correlation with luteinizing hormone and prolactin surges. (English) // Neuroendocrinology. - 1993. - Vol. 57, no. 4 . - P. 760-764. - PMID 8367038 .