切割穹窿海马伞大鼠海马内Lhx8 mRNA表达的变化

目的:探讨切割穹窿海马伞大鼠切割侧与正常侧海马内Lhx8 mRNA表达的差异。方法:切割SD大鼠右侧穹窿海马伞。切割后7d制备海马冰冻切片,用体外转录法制备地高辛标记的Lhx8 RNA探针进行原位杂交,分析切割侧和正常侧海马锥体细胞层和齿状回颗粒层中及齿状回门区和颗粒下层中的Lhx8 mRNA阳性细胞的数量和平均光密度值。结果:切割侧和正常侧海马锥体细胞层和齿状回颗粒层Lhx8 mRNA阳性细胞数量无明显差异,但切割侧平均光密度值较正常侧明显增加;在齿状回的门区和颗粒下层,切割侧Lhx8 mRNA阳性细胞数和平均光密度值均较正常侧升高。结论:切割穹窿海马伞后海马中Lhx8 mRNA表达上调,可能与其中的神经干细胞向胆碱能神经元分化的神经再生机制有关。

Change of Lhx8 mRNA expression in rat hippocampus after fimbria/fornix transection

Objective: To observe the difference of Lhx8 mRNA expression in hippocampus between the fimbria/fornix-transected side and nomal side. Methods: Six SD rats' right fimbriae were transected. On the 7th day after transection, the cryostat sections of hippocampus were prepared and hybridized in situ with digoxigenin-labeled Lhx8 RNA probe. In three random sections of each rat, the number and average optical density value of Lhx8 mRNA positive cells were measured in the pyramidal layer of hippocampus and granular layer of dentate gyrus as well as in the hilus and subgranular layer of dentate gyrus of both sides. Paired-Samples T test was used in statistictic analysis. Results: In the pyramidal layer of hippocampus and granular layer of dentate gyrus, Lhx8 mRNA was expressed strong in the transected side, though the same expression was also found in the normal side. No side difference was observed in the number of Lhx8 positive cell. In hilus and subgranular layer of dentate gyrus, not only the number of Lhx8 mRNA postive cells but also the average optical density value in the transected side were higher than those in the normal side. Conclusion: This data suggest that the increased expression of Lhx8 mRNA after fimbria/fornix transection might be related to the regeneration mechanism of neural stem cells differentiating into cholinergic neurons in hippocampus.