中文摘要：

目的探讨异氟醚对老龄大鼠海马CA3区突触结构的影响。方法雌性SD大鼠66只，22月龄，体重580—700g，随机分为2组（n=33）：对照组（C组）和异氟醚组（I组）。C组吸入含70％氧气的空气2h，I组通过异氟醚挥发罐的调节使麻醉箱内异氟醚浓度为3％，待翻正反射消失后将异氟醚浓度降至1．2％，维持2h。2组随机取30只大鼠，进行Y型迷宫测试，连续测试3d。于麻醉结束后1、3d（即Y型迷宫测试结束当天）2组随机取3只大鼠，取海马CA3区组织，电镜下观察突触界面结构。结果与C组比较，I组第1天和第2天时正确反应次数和主动回避次数均降低，第2天时全天总反应时间延长，学习能力降低，麻醉结束后第1天突触间隙宽度升高，突触后膜致密物质厚度降低（P〈0．05或0．01）。结论异氟醚可导致老龄大鼠认知功能减退，与海马CA3区突触后膜致密物质和突触间隙发生改变有关，但这些改变在麻醉结束后第3天均有所恢复。

英文摘要：

Objective To investigate the effect of isoflurane on the synaptic interface structure in hippocampal CA3 area in aged rats .Methods Sixty-six 22-month old SD rats weighing 580-700 g were randomly divided into 2 groups （n = 33 each）： control group （C） inhaled a gas mixture containing 70% 02 for 2 h and isoflurane group （ISO） inhaled 3 % isoflurane first and when fighting reflex was suppressed ISO concentration was reduced to 1.2% which was maintained for 2 h. Thirty animals were randomly selected from each group for Y-maze training. The training test was performed 20 times a day for 3 days. Three animals were randomly selected from each group after termination of anesthesia and were decapitated. The hippocampal CA3 area was isolated for examination with electron microscope. Results The correct reaction frequency and initiative avoidance frequency were significantly lower at day 1 and day 2, the total reactive time was longer at day 2 and the rate of acquiring the task was lower at day 3 in ISO group than in group C. The width of the synaptic cleft was significantly greater and the thickness of postsynaptie density lower in ISO group than in group C. Conclusion Isoflurane can induce cognitive hypofunction in the aged rats through the changes in synaptic interface in hippicampal CA3 area which recoverd to some extent 3 days after termination of anesthesia.