[Iba-1-immunopositive cells in rat pineal gland.]

The aim of this study was to investigate the morphofunctional organization of microglia and macrophages in the pineal gland of the rat brain using an immunohistochemical reaction to Iba-1. It was found that in the rat pineal gland, Iba-1-immunopositive cells are characterized by a rounded body and short thickened processes. Such morphology indicates their activated state, which is probably associated with the presence of fenestrated capillaries in the pineal gland and the need for more active monitoring and phagocytosis of pathogenic factors. Microglia/macrophages are predominantly localized in the perivascular space around blood vessels and are less commonly found in the parenchyma among pinealocytes. Another distinctive feature of the organization of Iba-1+-cells in the rat pineal gland was the formation of cell clusters. A small but significant decrease in the number of Iba-1+-cells with age was observed, which may be associated with possible dystrophic changes in these cells due to their active interaction with pathogens.