不同年龄大鼠大脑皮质损伤后的星形胶质细胞反应

THE AGE-DIFFERENCES OF ASTROCYTE REACTION TO STAB WOUND IN CEREBRAL CORTEX OF RAT

对幼年（３月龄）、成年（１２月龄）与老年（２７月龄）三组雄性Ｗｉｓｔａｒ大鼠的躯感皮质进行针刺后，在１～２１ｄ时间内用光镜与电镜观察损伤后的星形胶质细胞反应，探讨年龄因素对星形胶质细胞反应的影响。结果表明：反应性星形细胞在水肿、细胞分裂、吞噬、肥大与胶质界膜形成等方面均表现出程度上和发生时间上的年龄差异。幼年大鼠的星形细胞不仅水肿更为显著且出现更早，并且表现出向变性与最后死亡以及向代偿性合成增强两个方向发展、三组动物的星形细胞分裂活动以术后３ｄ最明显，尤以幼年组更多见，并出现活跃的吞噬现象．

The somatesthetic cortices of three age-groups (3, 12 and 27 months) male Wistar rats were stabbed with a syringe needle to determine whether the astrocyte reaction was different or not in various age-group during 1-21 post-injured days. The results indicated that the astrocytes showed apparent intracelullar edema, degeneration, cell mitosis, and hypertrophy. Intracelullar edema appeared earlier and more conspicuously in young rats than that in older ones, and the degenerative changes occurred more seriously even tending toward cell death especially in young animals. However, some edematous astrocytes shoed increase of cell organelles (mitochondria and ribosomes) after 3 days. Astrocyte mitosis appeared in all groups at three days but the most numerous mitotic figures presented in the marginal zone of injured region of young rats. The gliosis including intracelullar filament increasemay be seen in older animals, and a limiting membrane-like sheath around the injured region appeared more frequently in old rats.The different rates and degrees of structural repair in various age-groups could be related to the differences of astrocyte responding to needle wound.