【作者】 林蕾；

【导师】 张良成；

【作者基本信息】 福建医科大学 ， 麻醉学， 2010， 硕士

【摘要】 目的观察氯胺酮合用盐酸戊乙奎醚对新生大鼠学习记忆、海马CA3区突触素表达以及突触超微结构的影响。方法7d龄Sprague-Dawly(SD)大鼠100只,体重18~20g。随机分为4组,即①氯胺酮组(K组,n=25),予以氯胺酮50mg/Kg腹腔注射;②盐酸戊乙奎醚组(P组,n=25),予以盐酸戊乙奎醚2mg/Kg腹腔注射;③氯胺酮+盐酸戊乙奎醚组(PK组,n=25),予以氯胺酮50mg/Kg+盐酸戊乙奎醚2mg/Kg联合腹腔注射。以上3组药物均以生理盐水稀释成0.1mL/g容积;④生理盐水组(NS组,n=25)以等量体积的生理盐水腹腔注射。于给药后24h,每组大鼠随机选取5只快速断头取脑后行免疫组化测定海马CA3区突触素的表达和透射电镜观察海马CA3区突触数密度和超微结构的变化;余下的大鼠分别于给药后14d(Ⅰ期)、21d(Ⅱ期)进行行为学测试(包括Morris水迷宫实验、旷场实验及新物体识别实验),并且在给药后14d(行为学实验前)、28d(行为学实验后),每组大鼠再分别随机选取5只快速断头取脑,行与给药后24h相同的形态学观察。结果①水迷宫实验:在Ⅰ期测试中,逃逸潜伏期PK组最长,NS组和P组最短,K组居中;搜索策略中,边缘式、趋向式、随机式策略的使用4组间两两比较均无显著性差异,PK组采用直线式搜索策略明显少于NS组;探索时间PK组最短,NS组和P组最长,K组居中。在Ⅱ期测试中,训练合格率以NS组和P组最高,PK组最低,K组居中。②旷场实验:4组大鼠在Ⅰ期、Ⅱ期测试中各项指标差异无显著意义。③新物体识别实验:Ⅰ期偏好指数从高到低依次为NS组和P组、K组、PK组;Ⅱ期偏好指数4组大鼠间差异无显著意义。④突触素表达:给药后24h以NS组和P组最高,K组次之、PK组最低;给药后14d,4组大鼠突触素表达均比给药后24h有所增加,其中NS组和P组的增长趋势较快,K组和PK组的增长趋势较慢;给药后28d,4组大鼠突触素表达差异无显著意义。⑤突触的数密度及超微结构:给药后24h,PK组、K组的突触的数密度较低,突触间隙模糊不清或宽窄不一,未见明显突触后致密物,NS组和P组突触的数密度较高,突触间隙规则,可见少量的突触后致密物;给药后14d,4组大鼠均出现突触的数密度增加以及突触间隙变窄、突触活性区长度增长和突触后致密物厚度增加,但变化趋势以NS组和P组较快,K组和PK组较慢;给药后28d,4组大鼠突触的数密度和突触结构参数间无明显差异。给药后各时间点上述各项观察指标变化在NS组与P组间比较均无显著性差异。结论氯胺酮合用盐酸戊乙奎醚比单用氯胺酮更能抑制新生7d龄SD大鼠(相当于人类的婴儿期)学习记忆能力的发育、突触素表达和突触的数密度的增加、以及突触结构参数的优化。但随着年龄的增长以及适当的学习训练,到出生后35d(给药后28d,相当于人类的青春期),给药组大鼠的学习记忆能力与正常组无明显差异。更多还原

【Abstract】 Objective To observe the effects of using ketamine combined with penehyclidine hydrochloride in neonatal rats on developments of learning and memory、synaptophysin expression and synaptic ultrastructure in the region of hippocampal CA3.Methods One hundred seven-day-old Sprague-Dawly rats were randomly divided into four groups,( namely group K, group P, group PK, group NS)and intraperitoneally injected with 50mg/Kg of ketamine(group K),2mg/Kg of penehyclidine hydrochloride(group P), 50mg/Kg of ketamine plus 2mg/Kg of penehyclidine hydrochloride(group PK) or normal saline(group NS) respectively. The performances of every rat in neurological behavior (included with Open field,Novel objects recognition and Morris water maze) were tested at 14 days(phaseⅠ) and 21 days(phaseⅡ) after treatment.At the time points of 24-hr,14-day and 28-day after the medication, the immunhistochemical method was used for detecting the expression of synaptophysin in the region of hippocampal CA3, and synaptic numerical densities and synaptic ultrastructure also in the region of hippocampal CA3 were measured and observed under electron microscope.Results①Morris water maze tests at phase I, the escape latency in group K increased obviously compared to that in group NS or group P,and it increased further in group PK;oppositely,the preference index and the spatial probing time for previous platform in group K and group PK decreased remarkably compared to that in group NS or group P,especially for that in group PK.About searching strategies, there was no obvious difference for the indices of edge、trend、random strategies among four groups. The average percentage of straight strategy in group PK was significantly lower than that in group NS. Morris water maze tests at phaseⅡ, group PK performed worst, followed by group K, group NS and group P performed best.②There was no significant difference for the results in Open field tests among each group.③Novel object recognition tests at phase I, group NS and group P were the best, followed by group K, group PK performed worst. Results got in phaseⅡhad no significant difference among each group .④Compared with group NS and group P, the expression of synaptophysin in group K decreased significantly 24 hrs and 14 days after administration, and group PK was lower than group K. Up to 28 days after administration, the synaptophysin expression increased in all of the four groups and there were no significant differences between groups.⑤Compared with group NS and group P, group K showed significant decreases in synaptic numeric density、postsynaptic density thicknes and synaptic cleft 24 hrs and 14 days after administration, and group PK was lower than group K. Up to 28 days after administration, the synaptic ultrastructure optimized in all of the four groups and there were no significant differences between groups.There was no any significant difference for all indices at every time point mentioned above compared between group P and group NS. Conclusions The using of Ketamine together with penehyclidine hydrochloride or alone in neonatal rats both hindered the development of learning and memory、synaptophysin expression、synaptic numerical densities and the optimization of the synaptic ultrastructure in the region of hippocampal CA3, but the former did more significantly than the latter.However,the adverse effects mentioned aboved may diminished by learning、training and increasing of age, so that no difference was found for the adult rats in different groups.The administration of penehyclidine hydrochloride alone had no visibly disadvantageous effect on all the indices detected in this research.更多还原