Abstract:

Objective To observe the expression and distribution of SRY-related high-mobility-group-box-protein 2(SOX2), Nestin and BrdU positive cells in area postrema. Methods A total of 12 healthy 6-8 weeks old male SD rats were used in this study, 6 of which were treated with intraperitoneal injections of bromodeoxyuridine(BrdU), 50 mg/kg（0.3ml), two times a day for three days and other 6 were used as the control and treated with saline. After conventional heart perfusion, area postrema was detected by immunohistochemical staining and immunofluorescence staining for SOX2, Nestin and BrdU positive cells. Results Immunohistochemical staining indicated that SOX2 positive cells showed V shape distribution in the ventral part of area postrema. On the subpial of the back side, the dense cells were found with a zonal distribution. In the central part of area postrema, the positive cells were scattered and stained lighter. Nestin positive cells in the ventral part of area postrema showed V shape strongly positive color. Nestin showed weakly positive color in the central department of area postrema. The area postrema was visible with a small amount of BrdU positive cells. The SOX2 positive cells of area postrema were concentrated and shown the shape of the letter V in the ventral part. The cells were the divergence in expression in the central part. The visible positive expression of Nestin cells showed the shape of V distribution in the area postrema. Its positive immunoreactive products were granular and filaments. Immunofluorescence double staining demonstrated that in the SOX2 /BrdU fluorescence double staining specimen, SOX2 positive cells were densely distributed. Among the dense SOX2 positive cells, a small amount of SOX2/BrdU positive cells were scattered. In SOX2/Nestin fluorescence double staining specimens, SOX2 positive cells were densely distributed. The scattered distribution of SOX2/Nestin positive cells was seen in dense SOX2 positive cells. Conclusion SOX2 and Nestin positive cells show concentrated expression in area postrema. The positive cells in the ventral part show the shape of V dense distribution. BrdU labeled cells and SOX2/BrdU and SOX2/Nestin double labeled cells are visible in area postrema. These may support the existence of neural stem/progenitor cells in area postrema. 

Key words: Neural stem cell, Area postrema, SRY-related high-mobility-group-box-protein2, Nestin, Immunohistochemistry, Immunofluorescence, Rat