CAJ | 학술논문

目的探索幼年SD大鼠不同程度脱髓鞘对惊厥易患性的影响.方法选用21d幼鼠181只,按随机数字表法分为对照组和实验组,对照组给予正常饲料喂养2周(n=41)及4周(n=45),实验组给予含0.6％铜宗的饲料分别喂养2周(n=48)及4周(n=47)制备脱髓鞘模型.通过免疫组织化学及蛋白质印迹检测髓鞘碱性蛋白(MBP)含量,对脱髓鞘模型进行鉴定；利用匹罗卡品诱导大鼠惊厥发作,记录其出现惊厥的时间；膜片钳记录自无镁人工脑脊液(ACSF)诱导后海马脑片自发放电的潜伏期；利用视频-脑电图检测大鼠行为及其脑电图的改变；采用原位末端标记法(TUNEL法)观察海马神经元凋亡情况.结果免疫组织化学及蛋白质印迹检测结果显示,铜宗可导致海马及其胼胝体内髓鞘脱失,且铜宗4周组大鼠髓鞘脱失程度明显重于铜宗2周组.铜宗4周组大鼠经匹罗卡品诱发惊厥的潜伏期[(13.33 ±3.46) min]较其同龄对照组[(19.66 ±4.33) min]明显缩短(t =4.62,P＜0.01)；膜片钳测定结果发现,铜宗2周组大鼠自发放电潜伏期[(35.00±5.03) min]与同龄对照组[(49.86±10.65) min]相比明显缩短,差异有统计学意义(t=3.34,P＜0.05)；铜宗4周组与其同龄对照组相比,大鼠自发放电的潜伏期(min)亦明显缩短[19.29 ±3.95与51.86±10.79,t=7.50,P＜0.01],且较铜宗2周组缩短更为明显(t=6.50,P＜0.01)；通过视频及脑电图联合检测发现,7/11的铜宗2周组大鼠脑电图出现了癫痫样放电,铜宗4周组出现异常脑电图阳性率达10/10,同龄对照组脑电图均无异常；铜宗2周及4周组海马神经元TUNEL阳性细胞数与对照组相比,差异均无统计学意义.结论幼年大鼠脱髓鞘后,惊厥易患性明显增加,且脱髓鞘程度越重,惊厥潜伏期缩短更为明显,提示髓鞘的病变有可能是导致癫痫发生的可能机制之一.
목적 탐색유년SD대서불동정도탈수초대량궐역환성적영향.방법 선용21d유서181지,안수궤수자표법분위대조조화실험조,대조조급여정상사료위양2주(n=41)급4주(n=45),실험조급여함0.6％동종적사료분별위양2주(n=48)급4주(n=47)제비탈수초모형.통과면역조직화학급단백질인적검측수초감성단백(MBP)함량,대탈수초모형진행감정；이용필라잡품유도대서량궐발작,기록기출현량궐적시간；막편겸기록자무미인공뇌척액(ACSF)유도후해마뇌편자발방전적잠복기；이용시빈-뇌전도검측대서행위급기뇌전도적개변；채용원위말단표기법(TUNEL법)관찰해마신경원조망정황.결과 면역조직화학급단백질인적검측결과현시,동종가도치해마급기변지체내수초탈실,차동종4주조대서수초탈실정도명현중우동종2주조.동종4주조대서경필라잡품유발량궐적잠복기[(13.33 ±3.46) min]교기동령대조조[(19.66 ±4.33) min]명현축단(t =4.62,P＜0.01)；막편겸측정결과발현,동종2주조대서자발방전잠복기[(35.00±5.03) min]여동령대조조[(49.86±10.65) min]상비명현축단,차이유통계학의의(t=3.34,P＜0.05)；동종4주조여기동령대조조상비,대서자발방전적잠복기(min)역명현축단[19.29 ±3.95여51.86±10.79,t=7.50,P＜0.01],차교동종2주조축단경위명현(t=6.50,P＜0.01)；통과시빈급뇌전도연합검측발현,7/11적동종2주조대서뇌전도출현료전간양방전,동종4주조출현이상뇌전도양성솔체10/10,동령대조조뇌전도균무이상；동종2주급4주조해마신경원TUNEL양성세포수여대조조상비,차이균무통계학의의.결론 유년대서탈수초후,량궐역환성명현증가,차탈수초정도월중,량궐잠복기축단경위명현,제시수초적병변유가능시도치전간발생적가능궤제지일.
Objective To evaluate the effect of cuprizone-induced demyelination on seizure susceptibility in immature rats.Methods Demyelination model was induced in 21 d immature rats fed with 0.6％ cuprizone (CPZ) for 2 weeks (CPZ 2 weeks group) and 4 weeks (CPZ 4 weeks group).Morphological changes of myelinated fibers were examined using Gallyas staining.The expression of myelin basic protein (MBP) was determined by immunohistochemistry and western blot.The latency of seizure in CPZ rats induced by pilocarpine and the latency of spontaneous of discharge in hippocampus slices induced by Mg2+ free artificial cerebrospinal fluid (ACSF) were determined.In addition,behavior and epileptiform spikes were recorded by video-electroencephalogram monitoring.The apoptosis cells in hippocampus of rats were detected by TdT-mediated dutp nick end labeling (TUNEL).Results The results showed that myelinated fibers of the CPZ group were degenerated,and with significantly decreased MBP expression,related to control group rats.Besides,the MBP expression was decreased significantly in CPZ 2 weeks group compared to that of rats in CPZ 4 weeks group.The latency of seizure induced by pilocarpine was decreased in CPZ 4 weeks group ((13.33 ± 3.46) min) related to that in control group ((19.66 ± 4.33) min,t =4.62,P ＜ 0.01).In addition,the latency induced by Mg2+ free ACSF in hippocampus slice was significantly decreased in CPZ 2 weeks group ((35.00 ± 5.03) min vs (49.86 ± 10.65) min,t =3.34,P ＜ 0.05) and CPZ 4 weeks group ((19.29 ± 3.95) min vs (51.86 ± 10.78) min,t =7.50,P ＜ 0.01).While no spontaneous epileptiform spikes were observed in control group,abnormal discharge can be seen in 7/11 of CPZ 2 weeks rats and 10/10 of CPZ 4 weeks rats.Finally,there was no difference in the numbers of apoptosis cells in hippocampus between CPZ groups and control groups.Conclusions Immature rats treated with CPZ show increased seizure susceptibility which is strongly correlated with the severity of demyelination.Our study offers an insight that some relationship may be presentbetween demyelination and seizure.