小胶质细胞抑制剂Pexidartinib对小鼠遥远场景性恐惧记忆再巩固的影响  

Effect of microglia inhibitor Pexidartinib on reconsolidation of remote contextual fear memory in mice

作　　者：王来法 王雪琴 邓玲 张辉 崔艳慧 WANG Laifa;WANG Xueqin;DENG Ling;ZHANG Hui;CUI Yanhui(Neuroscience and Behavioral Research Center,Changsha Medical University,Changsha 410219,Hunan Province,China)

机构地区：[1]长沙医学院神经科学与行为学研究中心,湖南长沙410219

出　　处：《新乡医学院学报》2023年第12期1107-1113,共7页Journal of Xinxiang Medical University

基　　金：湖南省教育厅科学研究项目(编号:19C0220,19B069);长沙市自然科学基金资助项目(编号:kq2014117)。

摘　　要：目的探讨小胶质细胞抑制剂Pexidartinib对小鼠遥远场景性恐惧记忆再巩固的影响。方法将12只健康C57BL/6雄性小鼠随机分为实验组和对照组,每组6只。2组小鼠均置于场景恐惧反应箱中进行场景性恐惧条件化训练,构建场景性恐惧模型,并记录每次电击后小鼠的僵直时间;7 d后,实验组小鼠给予含Pexidartinib制剂PLX3397的鼠粮喂养,对照组小鼠给予普通鼠粮喂养,直至行为实验结果。场景性恐惧条件化训练后第16天,将小鼠重新放入场景恐惧反应箱中进行恐惧记忆唤起,不给予任何刺激呈现,小鼠自由探索5 min后取出,记录小鼠在此期间的僵直时间。在恐惧记忆唤起后24 h,将小鼠再次置于场景恐惧反应箱中,使其自由探索3 min,并记录其在该时间段所呈现的僵直时间。采用僵直时间百分比来表示小鼠的恐惧反应。行为实验结束后,腹腔注射戊巴比妥钠麻醉小鼠。2组各取3只小鼠迅速开胸暴露心脏,将灌注针自心尖插入左心室,使用4℃预冷的40 g·L^(-1)多聚甲醛(pH=7.4)进行灌注,至小鼠全身不自主抽动消失、全身肢体僵硬为止,取脑组织,多聚甲醛溶液固定,置于蔗糖溶液进行沉糖,然后用组织包埋剂包埋,采用免疫组织化学染色法检测2组小鼠海马中小胶质细胞数量。2组其余小鼠迅速断头取脑组织,冰上分离两侧海马组织,采用Western blot法检测小鼠海马组织中磷酸化溴结构域蛋白4(pBRD4)、消皮素D(GSDMD)、混合谱系激酶结构域样蛋白(MLKL)蛋白表达。结果在场景性恐惧条件化训练阶段,2组小鼠的僵直时间百分比均随足底电击次数的增加而升高(P<0.05),但2组小鼠第1、2、3、4、5次电击后的僵直时间百分比比较差异无统计学意义(P>0.05)。在唤起阶段,2组小鼠的僵直时间百分比比较差异无统计学意义(P>0.05)。在记忆检测阶段,实验组小鼠的僵直时间百分比显著低于对照组(P<0.05)。实验组小鼠海�Objective To investigate the effect of microglia inhibitor Pexidartinib on reconsolidation of remote contextual fear memory in mice.Methods Twelve healthy C57BL/6 male mice were randomly divided into experimental group and control group,with 6 mice in each group.The mice in the two groups underwent contextual fear conditioning training in the contextual fear response box to establish the contextual fear models,and the freezing time of mice after each footshock was recorded.After 7 days,the mice in the experimental group were fed with food containing Pexidartinib formulation PLX3397,while the mice in the control group were fed with regular food until the end of behavioral experiment.On the 16 th day after contextual fear conditioning training,the mice were put back into the contextual fear box for recalling the fear memory without any stimulation.The mice were taken out after 5 minutes of free exploration,and the freezing time of mice during this period was recorded.At 24 h after the fear memory was recalled,the mice were again placed in the contextual fear box,allowing them to explore freely for 3 minutes,and the freezing time of mice during this period was recorded;the fear response of mice was indicated by the percentage of freezing time.After the behavioral experiment,the mice were anesthetized by intraperitoneal injection of pentobarbital sodium,and three mice from the two groups were taken and rapidly opened the chest to expose their hearts,the perfusion needle was inserted into the left ventricle from the tip of heart and then was perfuse with 40 g·L^(-1) paraformaldehyde(pH=7.4)which precooled at 4℃until the involuntary convulsion disappeared and the body limbs of mice were stiff.The brain tissue of mice was taken and fixed with paraformaldehyde solution,and then placed in sucrose solution for dehydration.The brain tissue of mice was coated with tissue embedding agent.The number of microglial cells in the hippocampus of mice in the two groups was detected by immunohistochemistry.The remaining mice in th

关 键 词：小胶质细胞 Pexidartinib 遥远场景性恐惧 记忆再巩固 磷酸化溴结构域蛋白4 消皮素D 混合谱系激酶结构域样蛋白 

分 类 号：R749[医药卫生—神经病学与精神病学]