Structural Characteristic of Nucleolus and Heterochromatin Aggregates of Rat Brain Tanycytes

This work was aimed at studying the structural organization of nucleolus and constitutive heterochromatin in different types of tanycytes during postnatal development and aging of rats. The distribution of nucleolus argentophilic proteins (nucleolin and nucleophosmin) and heterochromatin aggregates in tanycytes at various stages of postnatal development have been described for the first time using immunohistochemical methods and confocal laser microscopy. The heterogeneity of the size and number of nucleoli was demonstrated both in different tanycytes subpopulations and at different ages of an animal. This may indicate different levels of the tanycyte synthetic activity and the ability to proliferate during early postnatal development and aging. During aging, the distribution of heterochromatin aggregates varies among tanycyte subpopulations: alpha-tanycytes undergo intense heterochromatization, while beta-tanycytes are characterized by a stable organization of the studied compartments of the cell nucleus. The data obtained significantly supplement the modern understanding of organization of the structure of the cell nucleus of tanycytes during normal development and aging. This can subsequently serve as a basis for establishing the role of these subnuclear structures in pathological processes.