切除嗅球对成年大鼠嘴侧迁移流的影响

THE EFFECTS OF OLFACTORY BULB REMOVAL ON ROSTRAL MIGRATORY STREAM IN ADULT RAT BRAIN

我们以前的研究观察到嗅球切除后室管膜下层(SVZ)仍能产生新细胞,但新细胞迁移的通路尚不清楚。为此,本研究建立了成年SD雄性大鼠右侧嗅球切除模型,利用Nissl染色、PSA-NCAM和GFAP免疫组织化学染色的方法观察了成年SD大鼠嗅球切除后存活不同时间两侧嘴侧迁移流(RMS)的形态学特征及RMS细胞的密度和单个细胞的面积,并进行统计学分析;同时利用Westernblot方法检测PSA-NCAM在RMS的表达。结果观察到:(1)嗅球切除后不同时间点,嗅球切除侧RMS的细胞数和面积增加,PSA-NCAM免疫阳性细胞数增加,而GFAP免疫阳性细胞数在嗅球切除后2周和4周有明显增加;(2)嗅球切除后两侧RMS的细胞密度和单个细胞的面积没有明显改变;(3)从矢状切片可见嗅球切除后RMS的形态和路径没有明显改变,但在切除断端细胞堆积明显。这些结果提示嗅球切除后仍有年轻神经元沿RMS向嘴侧迁移,SVZ的神经生发活动与嗅球的存在与否可能没有必然的联系。

We have found that new neurons were still produced after the olfactory bulb （OB） removal. However, little is known about the changes in the rostral migratory stream （RMS） through which the new neurons produced in the subventreular zoon （SVZ） migrated into the OB. Thus, an animal model of OB removal was created, Nissl staining and immunohistochemistry for showing polysialylated form of the neural cell adhesion molecule （PSA-NCAM） and glial fibrillary acidic protein （GFAP） were done in the brain tissue from adult OB removal rats and observed under light-microscope. Total cell number and the number of PSA-NCAM and GFAP-positive cells in the two sides of RMS were counted and analyzed, and the cell density and area of each cell in the RMS were measured. In addition, Western blot was used to detect the expression of PSA-NCAM on both sides of RMS in the animal model. The results showed that ： （ 1 ） The total cell number and the PSA-NCAM-positive cell number in the right side of the RMS in the rats of OB removal increased than the left one, and the GFAP-positive cell number increased 2 w and 4 w after OB removal. （ 2 ） The density and area of each cell on both sides of RMS had no change. （ 3 ） The morphology and routine of the RMS after OB removal did not change, but cells accumulated apparently at the edge of the lesion. These results suggest that young neurons still migrate along the RMS after the OB removal and OB is not essential for the neurogenesis in the SVZ.