Age-Related Features of GFAP and DCX Expression in Rats’ Olfactory Bulbs and Rostral Migratory Stream

Abstract

The aim of the study was to establish the normative parameters of the astrocytes’ and neuroblasts’ distribution in the rostral migratory stream and in different layers of the rats’ olfactory bulbs in the evolutionary period by the positivity of the specific GFAP and DCX markers and to identify possible correlations between the GFAP and DCX expression levels. Material and methods. The olfactory bulbs of twenty male Wistar rats of 30-, 60-, 90-, 180-day-old age were used as the study material. These groups correspond to the infantile, juvenile and mature ages. The distribution of GFAP, a marker of astrocytes and DCX, a marker of immature neurons, in olfactory bulbs and a rostral migratory stream were investigated. These markers were detected on the parasagittal sections with distribution for olfactory bulb layers. The numerical density of GFAP+ astrocytes (cell/mm 2 ), the area of their processes’ distribution, the bodies’ average sizes and the numerical density of DCX+ neurons (cell/mm 2 ) were determined. Results. As a result age-related normative characteristics of astrocyte density, median distribution of their processes and numerical density of immature neurons were established. Correlations between expression of DCX and GFAP in rostral stream and granular layer of olfactory bulb were recognized. According to the received data the peak of postnatal neurogenesis intensity occurs at the juvenile age (60-90 days). The numerical density of neuroblasts depends on the layer of the bulb and the age of the animal. The numerical density of astrocytes also has topographic and age features, the area of distribution of the processes of astrocytes varies in opposition to their numerical density. The results obtained are the basis for assessing the response of glia and stem niches to different types of effects.