孕晚期七氟烷麻醉对子代大鼠海马CA3区神经元树突棘结构及认知功能的影响

Effects of sevoflurane anesthesia in the third trimester of pregnancy on the dendritic spine structure and cognitive function of hippocampal CA3 neurons in offspring rats

目的 探讨孕晚期七氟烷麻醉对子代大鼠海马CA3区神经元树突棘结构及认知功能的影响。方法 将30只孕鼠随机分为对照组、七氟烷吸入4 h组和七氟烷吸入7 h组,每组各10只。2个实验组分别在孕18 d时每天持续吸入3%七氟烷4 h和7 h,对照组仅吸入氧气7 h,所有孕鼠均干预3 d。每组各取子代大鼠10只,用Morris水迷宫检测学习记忆能力;取大鼠海马CA3区,Golgi染色观察神经元树突棘结构;western-blot检测突触可塑性蛋白[突触后致密蛋白95(PSD95)、脑源性神经营养因子(BDNF)、酪氨酸激酶受体B(TrkB)、Ras同源基因家族成员A(RhoA)、Rho关联卷曲螺旋蛋白激酶2(ROCK2)]表达水平。结果 与对照组比较,七氟烷吸入4 h组、七氟烷吸入7 h组平台象限停留时间和穿平台次数较低(P<0.05),而逃避潜伏期较长(P<0.05)。与七氟烷吸入4 h组比较,七氟烷吸入7 h组平台象限停留时间和穿平台次数较低(P<0.05),而逃避潜伏期较长(P<0.05)。与对照组比较,七氟烷吸入4 h组和七氟烷吸入7 h组树突棘密度和树突分支降低(P<0.05),而树突棘长度增加(P<0.05)。七氟烷吸入7 h组树突棘密度和树突分支比七氟烷吸入4 h组低,而树突棘长度较长(P<0.05)。与对照组比较,七氟烷吸入4 h组和七氟烷吸入7 h组的PSD95、BDNF、p-TrkB、TrkB表达水平较低(P<0.05),而RhoA和ROCK2表达水平较高(P<0.05)。与七氟烷吸入4 h组比较,七氟烷吸入7 h组PSD95、BDNF、p-TrkB、TrkB表达水平较低(P<0.05),而RhoA和ROCK2表达水平较高(P<0.05)。结论 孕晚期七氟烷麻醉可能会影响子代大鼠学习记忆能力,与海马CA3区树突棘结构损伤有关。

Objective To investigate the effects of sevoflurane anesthesia in the third trimester of pregnancy on the structure and cognitive function of dendritic spines in hippocampal CA3 area of offspring rats. Methods Thirty pregnant mice were randomly divided into control group,inhale 3% sevoflurance for 4 hours and 7 hours group,10 in each group. On the 18th day of pregnancy,the experimental group 1 continued to inhale 3% sevoflurane for 4 hours a day,the experimental group 1 continued to inhale 3% sevoflurane for 4 hours and 7 hours a day,respectively. All pregnant mice were intervened for 3 days. Each group of 10 offspring rats was used to test the learning and memory ability with Morris water maze;the CA3region of the hippocampus of the rats was taken,and Golgi staining was used to observe the structure of neuronal dendritic spines. Western-blot detection of synaptic plasticity proteins[postsynaptic dense protein 95(PSD95),brain-derived neurotrophic factor(BDNF),tyrosine kinase receptor B(TrkB),Ras homologous gene family member A(RhoA),Rho-associated coiled-coil kinase 2(ROCK2)]expression levels. Results Compared with control group,inhale 3% sevoflurance for 4hours and 7 hours group had lower platform quadrant stay time and times of crossing the platform(P<0.05),while escape latency was longer(P<0.05). Compared with inhale 3% sevoflurance for 4 hours,inhale 3% sevoflurance for 7 hours group had lower platform quadrant stay time and times of crossing the platform(P<0.05),while escape latency was longer(P<0.05). Compared with the control group,the density of dendritic spines and dendritic branches in inhale 3% sevoflurance for4 hours and 7 hours group decreased(P<0.05),while the length of dendritic spines increased(P<0.05). The density of dendritic spines and dendritic branches in inhale 3% sevoflurance for 8 hours group were lower than those in inhale 3% sevoflurance for 7 hours group,while the length of dendritic spines was longer(P<0.05). Compared with the control group,the expression levels of PSD95,BDNF,p-TrkB and TrkB in inhale 3% sevoflurance for 4 hours and 7 hours group were lower(P<0.05),while the expression levels of RhoA and ROCK2 were higher(P<0.05). Compared with inhale 3% sevoflurance for 4 hours group,the expression levels of PSD95,BDNF,p-TrkB and TrkB in inhale 3% sevoflurance for 8 hours group were lower(P<0.05),while the expression levels of RhoA and ROCK2 were higher(P<0.05). Conclusion Sevoflurane anesthesia in the third trimester can affect the learning and memory ability of offspring rats,which is related to the damage of dendritic spine structure in hippocampal CA3 area.