The morphology of choroid plexuses of rats’ brain's ventricles at the first year of the development

Choroid plexuses of brain ventricles play a special role in the functioning of various brain structures and the formation of cerebrospinal fluid. Through the cerebrospinal fluid, biological, immunological, protective functions are realized. Any deficiency in its production in laboratory animals leads to malnutrition of the brain and spinal cord and impaired adaptive behavior. From this point of view, the study of the features of the structural organization of the choroid plexuses of the ventricles of the brain in laboratory animals in the age aspect seems relevant. The objects of the study were 134 white Wistar rats of different ages - 3, 10, 28 days and 5, 8, 12 months of postnatal development. A histological morphometric study of the choroid plexuses of the ventricles of the brain was carried out. To assess the age-related dynamics of the volume of the cerebral ventricles, sections were selected in which their cross-sectional area was maximum, the values of the indicator were determined on digitized microphotographs with a fourfold increase by tracing the boundaries of the ventricles of subsequent calculations in the Image J morphometric computer program. Determination of volumetric fractions of the choroid plexuses in the ventricles of the brain was carried out stereologically on serial sections using an eyepiece grid with 60 equidistant intersection nodes at a magnification of 400 times. The results of the study indicate that after birth, the choroid plexuses of the ventricles of the brain of Wistar rats develop as an integral tissue system, the most intense changes were noted in the lateral ventricles during the first month of life of the animals. The lateral ventricles are characterized by an accelerated growth in size, outstripping the rate of development of the choroid plexuses. According to the calculations, the increase in the volume of the choroid plexus is largely due to the growth of blood vessels and connective tissue. In the III and IV ventricles, a similar trend is traced, but this process is less pronounced. Since the choroid plexuses are a source of cerebrospinal fluid formation, the revealed quantitative patterns indicate the age-related involution of the ventricles of the brain, which possibly leads to a decrease in the functional activity of their choroid plexuses and impaired cerebrospinal fluid dynamics.