Proliferative Markers and Neural Stem Cells Markers in Tanycytes of the Third Cerebral Ventricle in Rats.

The proliferative properties of tanycyte subpopulations during postnatal development and aging were studied. Using immunohistochemical markers, we described the distribution of proliferative markers and markers of neural stem cells (NSC) in 4 tanycyte subpopulations (α1-, α2-, ß1-, and ß2-tanycytes). During the first postnatal week, all tanycyte subpopulations exhibit proliferative activity. During aging, ß-tanycytes lose their proliferative activity and retain a limited set of NSC markers, whereas α-tanycytes maintain both the ability to proliferate and the properties of NSC throughout the entire postnatal development including aging. The data obtained significantly improve modern understanding of the proliferative potential of tanycytes and their subpopulation differences in early postnatal period and during aging.

[Mast cells of the human pineal gland.]

The purpose of this study was to assess the possibilities of identifying mast cells using different histochemical and immunohistochemical methods and elucidating the features of their localization in the human pineal gland. The undertaken study showed that mast cells are an essential component of the human pineal gland, regardless of age. The data obtained indicate an increase in the number of mast cells in the pineal gland with age. Mast cells are mostly located in the pineal stroma and their preferred location has not been related to concrements, cysts or melanin accumulations. Mast cells in the pineal gland are predominantly non-degranulating, which indicates their inactive state. The detectability of mast cells in the pineal gland depended significantly on the applied method of staining of the preparations. The largest number of mast cells was revealed by tryptase immunohistochemistry, which should be used to accurately determine the population of mast cells of the pineal gland.