CAJ | 학술논문

目的探讨大鼠健侧颈7移位术后运动皮层兴奋性谷氨基酸及其受体变化规律.方法建立颈胸椎后路左侧全臂丛根性撕脱伤和健侧颈7移位正中神经大鼠模型,分别于术后不同时间采用肌电图检测观察正中神经功能的恢复,同时运用运动皮层区微电极刺激法明确大鼠患肢皮层代表区在术后的变化.根据运动皮层区微电极刺激的结果,选择4个皮层重组特异时间点进行取材,行大鼠脑片初级运动皮层区谷氨酸神经元及N-甲基-D-天门冬氨酸受体(NR1、NR2A、NR2B)的免疫组织化学染色.结果大鼠健侧颈7移位术后,随时间的延长,患侧指深屈肌复合肌肉动作电位潜伏期缩短,波幅升高.术后4个月组,5只大鼠中有3只患爪支配区仅位于同侧运动皮层,同时各手术组双侧运动皮层NR1表达水平均增高,与对照组相比差异有统计学意义(P<0.05).其中右侧运动皮层NR1表达升高显著,与同组对侧相比差异有统计学意义(P<0.05).术后7个月组,4只大鼠患爪支配区位于双侧运动皮层,而且各手术组右侧运动皮层NR2A表达水平升高,与健康大鼠同侧皮层或同组大鼠对侧皮层比较差异均有统计学意义(P<0.05),健侧颈7移位组大鼠右侧皮层NR2A表达水平,较单纯臂丛撕脱或臂丛撕脱健侧颈7切断组同侧皮层升高明显,差异有统计学意义(P<0.05).术后10个月组,3只大鼠患爪支配区位于对侧运动皮层,而在同侧运动皮层却未测到,同时健侧颈7移位组大鼠右侧皮层NR2A表达水平仍维持在升高水平,与其他各组大鼠同侧或同组对侧比较,差异有统计学意义(P<0.05).结论大鼠全臂丛根性撕脱伤健侧颈7移位正中神经后,大脑发生跨两半球的功能重塑.NR1和NR2A表达的增高可能分别在术后初期和后期功能重组中发挥了一定的作用.
목적 탐토대서건측경7이위술후운동피층흥강성곡안기산급기수체변화규률.방법 건립경흉추후로좌측전비총근성시탈상화건측경7이위정중신경대서모형,분별우술후불동시간채용기전도검측관찰정중신경공능적회복,동시운용운동피층구미전겁자격법명학대서환지피층대표구재술후적변화.근거운동피층구미전겁자격적결과,선택4개피층중조특이시간점진행취재,행대서뇌편초급운동피층구곡안산신경원급N-갑기-D-천문동안산수체(NR1、NR2A、NR2B)적면역조직화학염색.결과 대서건측경7이위술후,수시간적연장,환측지심굴기복합기육동작전위잠복기축단,파폭승고.술후4개월조,5지대서중유3지환조지배구부위우동측운동피층,동시각수술조쌍측운동피층NR1표체수평균증고,여대조조상비차이유통계학의의(P<0.05).기중우측운동피층NR1표체승고현저,여동조대측상비차이유통계학의의(P<0.05).술후7개월조,4지대서환조지배구위우쌍측운동피층,이차각수술조우측운동피층NR2A표체수평승고,여건강대서동측피층혹동조대서대측피층비교차이균유통계학의의(P<0.05),건측경7이위조대서우측피층NR2A표체수평,교단순비총시탈혹비총시탈건측경7절단조동측피층승고명현,차이유통계학의의(P<0.05).술후10개월조,3지대서환조지배구위우대측운동피층,이재동측운동피층각미측도,동시건측경7이위조대서우측피층NR2A표체수평잉유지재승고수평,여기타각조대서동측혹동조대측비교,차이유통계학의의(P<0.05).결론 대서전비총근성시탈상건측경7이위정중신경후,대뇌발생과량반구적공능중소.NR1화NR2A표체적증고가능분별재술후초기화후기공능중조중발휘료일정적작용.
Objective To explore the changes of glutamic acid and NMDA receptor expression in motor cortex following contralateral C7 transfer. Methods Total root avulsion of the left brachial plexus and transfer of the right C7 nerve root to the left median nerve via ulnar nerve graft was established in a rat model. Recovery of median nerve function was monitored with electrophysiologic examination at various postoperative intervals. Representation of the injured forepaw was mapped using intracortical microstimulation (ICMS). According to the ICMS results, brain samples were harvested for determination of glutamic acid and NMDA receptors (NR1、 NR2A、NR2B)in motor cortex by immuno-histochemical assay. Results After the surgery recovery of flexor digitorum profundus was indicated by decrease in compound muscle action potential (CAMP) latency and increase in CMAP amplitude over time. At 4 months, median nerve representation region of the affected forelimb appeared in the ipsilateral motor cortex in 3 rats and upregulation of NR1 was observed in both hemispheres of all rats from the operative groups. The NR1 expression showed significant change in the normal and operative groups. Meanwhile, NR1 expression in the right cortex was significantly higher than that in the left cortex. At 7 months, both hemispheres of cortex activated the injured forepaw in 4 rats. There was a significant increase in NB2A expression in the right motor cortex in the operative groups and NR2A expression in rats following contralateral C7 transfer was significantly higher than that in the rats from the other operative groups. At 10 months, the contralateral motor cortex exclusively controlled the injured forepaw and the expression of NR2A was still up-regulated. NR2A expression in rats following contralateral C7 transfer was still significantly higher than that in the rats from the other operative groups. Conclusion Transhemispheric functional reorganization of the motor cortex is confirmed in rats following contralateral C7 transfer. NR1 plays an important role in the primary cortical plasticity and NR2A is needed to continue this reorganization in later stage.