The Expression Pattern Of Nestin NSE GFAP In The Rat Brain From Embryo To Newborn

Objective To investigate the percentages of Nestin NSE GFAP in rat brain at different developmental stages and reveal how they distribute, which will add to the further understanding of the neural ontogeny in brain in mammalian, contribute to the research on how to condition neural stem cells (NSCs) to produce selective lineages, facilitate the applying research about rat to human being, and find effective strategies to isolate, enrich and propagate homogeneous populations of neural stem cells in vitro. Method Wistar rats were grouped into eleven parts according to developmental stage they were at: E12, E14, E16, E18, E20, P1, P3, P5, P7, P9, P90. Integral brains were microsurgically obtained. On the one hand, the brains were immediately fixed in 4% paraformaldehyde, embedded with paraffin and cut into 4-um-sheet tissue sections. The sections were then immunohistochemically stained following the directions of the SABC kits provided by Boster Biotech Company in Wuhan, China. On the other hand, the brains were made into single cell suspensions. Nestin, NSE, GFAP antigens in the suspensions were combined respectively with monoclonal antibodies, the compounds were then fixed with the secondary antibodies IgG conjugated to FITC, and then determined with cytometry. Results 1. Nestin was expressed from E12 to P9, the whole investigated period. The expression fluctuated with two summits, E12 and E16 to E18. The level of Nestin expressed by the prenatal on the whole was much higher than that of the postnatal. Nestin-positive cells in E12 were mainly located at the outskirts of the mantle zone and neural crest. They migrated to specific locations in E16. 2. NSE-positive cells began to be evidently detected since E14, resided in some specific areas amidst net structure. They were found having migrated to beneath cortex in E16. The percentage of NSE-positive cells in P3 was the highest compared with that of the other developmental stages. 3. A few GFAP-positive cells were found in E12, about 12.84%. However, a higher-level expression of GFAP was not detected until E16. The expression increased stably and tended to reach the level of P90, the control. Conclusion: 1. The expression of Nestin in the rat brain occurs at early stage of embryo, fluctuates during the investigated period with two summits, E12 and E16 to E18. The percentages decrease drastically after born so much so that the level of P9 almost reaches that of P90, the adult. 2. Neurons cannot be obviously identified until E14, they mainly located at between ectoderm and neural tube, migrate to beneath cortex in E16. The percentages of NSE-positive cells fluctuate from E14 to P9, P3 at the summit. 3. Radial glia-like (RGC) might be found at early stages of embryo development. 4. Astrocytes show their appearances at E16, the percentage shared by them increases since E16 and gradually reach the level of P90, the adult.