Structural peculiarities of the vascular plexuses of the cerebral ventricles during postnatal ontogenesis

Aim: To study the structural features of vascular plexuses of the cerebral ventricles at different stages of ontogenesis.

Materials and Methods: The results of the study were obtained by examining the vascular plexuses of the ventricles of the human brain. Brain specimens from people aged up to 86 years were examined. Macro-, micro- and submicroscopic, light-optical, and statistical methods were used to establish the morphological features of the structure and innervation and to identify the nerve-receptor apparatus of the vessels and tissue substrate of the vascular plexuses of the human brain ventricles at different stages of ontogenesis.

Results: Research has shown that the vascular plexuses of the ventricles of the human brain consist of epithelium and connective tissue with a large number of blood vessels. The plexus has villous and non-villous parts. The epithelium is represented by light and dark cells of cubic and flattened shape. The stroma of the vascular p lexus consists of collagen fibrils, protofibrils, and fibers enclosed in the ground substance. Fibroblasts are located here singly and in groups. A large number of microvilli and cilia are found on the apical surface of epithelial cells. The nuclei of epithelial cells are located near the basement membrane of the epithelium and can take on various shapes. Contacts between epithelial cells are most often in the form of tight junctions. A small number of macrophages and mast cells are found at the border with epithelial cells. It should be noted that vascular plexuses, in terms of vascularization, are organs with dual blood supply (trophic and functional). The basis of the vascular plexus is formed by blood vessels, which, after entering the thickness of the plexus, branch off from the main vessels running along the plexus into a microcirculatory bed with a highly complex structure. We have established that the diameters of microvessels undergo changes during ontogenesis that correlate with changes in the plexus itself, occurring simultaneously with the development of the brain.

Conclussions: The basis of the vascular plexuses of the cerebral ventricles is formed by a collection of blood vessels - from muscular arteries to capillaries, which come into contact with the ependymal epithelium in the villi of the plexus. The microcirculatory bed is adapted to its connective tissue environment and is closely functionally related to the epithelium of the vascular organ. Capillaries with polar arrangement of fenestrated endothelial cells on the side of the vascular plexus epithelium predominate, indicating their active transport function and participation in the function of the blood-cerebrospinal fluid barrier as part of the blood-brain barrier. Microvessels undergo changes during ontogenesis that correlate with changes in the plexus itself, which occur simultaneously with the development of the brain and reflect the functional loads of the vascular plexus.