大鼠视神经钳伤后外侧膝状体细胞损伤的研究

目的　探讨大鼠视神经钳伤后 ,外侧膝状体 (lateralgeniculatebody,LGB)细胞的损伤情况。方法　用 4 0g视神经损伤钳 ,压迫Sprague Dawley(SD)大鼠双侧视神经 30s,制成视神经部分定量损伤的动物模型。对LGB连续梯度切片 ,7d后用末端脱氧核苷酸转移酶介导的dUTP缺口末端标记法 (teriminaldeoxynucleotidyltransferase mediateddUTPnickend labeling ,TUNEL)对LGB细胞进行凋亡检测。 1个月后通过免疫组化染色技术 ,用兔抗鼠神经丝 (neurofilament,NF)单克隆抗体对LGB的神经元进行检测。同时经视觉中枢注入荧光染料颗粒蓝 ,对LGB细胞进行逆行荧光标记 ,在 70 0nm波长荧光显微镜下对连续切片的LGB标记细胞进行平均密度计数 ,并与对照组比较。结果　TUNEL法染色证实LGB细胞发生凋亡。对照组神经丝免疫组化染色呈清晰的条索状 ,而实验组明显减少。对照组LGB细胞密度均值为 (5 172± 2 4 8)个 /mm2 ,而损伤组LGB细胞密度均值为 (414 4± 6 1)个 /mm2 ,两组比较差异有非常显著意义 (t=8 995 ,P <0 0 1)。结论　在大鼠视神经钳伤后 ,LGB细胞受损 ,其损伤机制与凋亡有关

Alteration of lateral geniculate body cells after partial injury

OBJECTIVE: To investigate the damage of the cells of the lateral geniculate bodies (LGB) of Sprague-Dawley (SD) rats after partial optic nerve injury. METHODS: The optic nerve was pressed by a forceps (40 g) for 30 seconds to set up the animal model with optic nerve injury. LGB was chopped in serial coronal slices (10 microm thickness) by a cryomicrotome. The apoptosis of LGB cells was detected with terminal deoxynucleotidyl transferase (TDT)-mediated dUTP nick end-labeling (TUNEL) technique after one week. After retrograde labeling with Granular Blue (GB) through injecting GB into optic center, the average density of the LGB cells was counted under the fluorescent microscope. Using monoclonal rabbit anti-rat neurofilament (NF) antibody, the neurons of LGB were detected by immunochemistry stains, and the standard avidin-biotin complex immunoperoxidase technique was used for immunostaining. RESULTS: The results of TUNEL analysis showed that the mechanism of the LGB cells pathogenesis was apoptosis. The LGB cells appeared clear striation in the control group, and the cells in experimental group decreased obviously after immunohistrochemical staining. The average density of LGB cells was (5 172 +/- 248) cells/mm(2) in control group, and (4 144 +/- 61) cells/mm(2) in experimental group. CONCLUSION: After partial optic nerve injury, the LGB cells are obviously damaged, which may be related to apoptosis of LGB cells.