亚麻醉浓度七氟烷对青少年期大鼠前额皮质神经元树突棘可塑性的影响

Effects of subanesthetic concentration of sevoflurane on plasticity of dendritic spines in prefrontal cortex neurons of juvenile rats

目的探讨吸入亚麻醉浓度七氟烷对青少年期大鼠前额皮质树突棘可塑性的影响。方法清洁级雄性SD大鼠36只,24日龄,体重50~60 g,采用随机数字表法分为2组(n=18):对照组(C组)和七氟烷麻醉组(S组)。S组吸入1.2%七氟烷3 h,氧浓度50%,流量为1 L/min,C组吸入50%氧气3 h,流量为1 L/min。麻醉3 d后行旷场实验和Morris水迷宫实验,随后处死大鼠,取大脑组织,分别采用TUNEL染色法、高尔基染色法和Western blot法测定前额皮质Ⅱ-Ⅲ层凋亡神经细胞计数、神经元树突棘密度和突触后致密蛋白95、桥尾蛋白的表达水平。结果与C组比较,S组旷场实验中运动总距离、中央区停留时间、Morris水迷宫中平均游泳速度、逃避潜伏期和凋亡神经细胞计数差异无统计学意义(P>0.05),树突棘密度增加,突触后致密蛋白95和桥尾蛋白的表达上调(P<0.05)。结论亚麻醉浓度七氟烷可增强青少年期大鼠前额皮质神经元树突棘可塑性。

Objective To investigate the effects of subanesthetic concentration of sevoflurane on the plasticity of dendritic spines in the prefrontal cortex neurons of juvenile rats.Methods Thirty-six clean-grade male Sprague-Dawley rats,aged 24 days,weighing 50-60 g,were divided into control group(group C)and sevoflurane anesthesia group(group S)using a random number table method,with 18 rats in each group.Group S inhaled 1.2%sevoflurane and 50%oxygen(flow rate 1 L/min)for 3 h,while group C inhaled 50%oxygen(flow rate 1 L/min)for 3 h.Open-field test and Morris water maze test were performed at 3 days after anesthesia.Animals were sacrificed,and brain samples were then taken for determination of the number of apoptotic neurons in layerⅡ-Ⅲof the prefrontal cortex,density of dendritic spines,and expression of postsynaptic density protein 95 and gephyrin by TUNEL staining,Golgi staining or Western blot.Results Compared with group C,no significant change was found in total distance or time of staying at the central region in the open-field test or the average swimming velocity,escape latency or the number of apoptotic neurons in the Morris water maze test(P>0.05),and the density of dendritic spines was significantly increased,and the expression of postsynaptic density protein 95 and gephyrin was up-regulated in group S(P<0.05).Conclusion Subanesthetic concentration of sevoflurane can enhance the plasticity of dendritic spines in the prefrontal cortex neurons of juvenile rats.