大鼠脊髓胶质瘢痕形成的规律

Formation of glial scar in the rat spinal cord after injury

背景:脊髓损伤后治疗不理想的原因是脊髓组织的囊变和胶质瘢痕的形成,因此,明确胶质瘢痕的发生发展规律具有重要意义。目的:观察大鼠脊髓损伤后脊髓胶质瘢痕形成的空间分布、时间规律,以及轴突变化特征。方法:采用改良Allen重物坠落法建立SD大鼠脊髓损伤模型,分别于损伤后1d,3d,5d,1周,2周,4周,6周,8周,10周,12周取材。以正常饲养的大鼠作对照。结果与结论:大鼠脊髓损伤后4周开始出现致密瘢痕增生,之后瘢痕厚度平稳下降,至损伤后10周形成光滑的囊腔壁,囊腔内无胶质纤维酸性蛋白阳性星形胶质细胞,损伤区囊腔周围的胶质瘢痕内可见密集肥大的星形胶质细胞,未见神经丝蛋白阳性轴突位于囊腔内。提示脊髓损伤后4周胶质瘢痕厚度达到高峰,囊腔与残存轴突之间开始形成机械屏障,损伤后10周瘢痕厚度趋于稳定。

BACKGROUND： After spinal cord injury, the treatment cannot completely solve the problem with the body because glial scar forms and cystic degeneration occurs in the spinal cord tissue. Therefore, it is of great significance to know the regularity of glial scar development. OBJECTIVE： To analyze the spatial distribution, characteristics of axon and time characteristics of glial scar in the rat spinal cord after experimental spinal cord injury. METHODS： SD rats were divided into control group, 1-day group, 3-day group, 5-day group, 1-week group, 2-week group, 4-week group, 6-week group, 8-week group, 10-week group and 12-week group. Allen’s weight-drop method was performed to prepare spinal cord injury models in rats expect the control group. RESULTS AND CONCLUSION： At 4 weeks after spinal cord injury, glial scar and smooth cavity wall began to form. No astrocytes positive for glial fibrillary acidic protein and axons positive for neurofilament protein existed inside the cavity. The glial scar begun to stabilize at 4 weeks after spinal cord injury, and mechanical barriers between the cavity and axon came into being. Thickness of the glial scar no more increased at 10 weeks after spinal cord injury.