切断海马伞对大鼠硬性脑挫伤后运动行为恢复的影响

Influence of transsection of fimbria-fornix on the recovery of locomotive equilibrium ability after traumatic brain injury in rats

硬性挫伤运动皮层诱发大鼠偏瘫及其随后的行为代偿是研究中枢神经可塑性的一个理想模型。本工作观察了切断海马伞对脑挫伤后行为恢复的影响。结果表明 :与对照组相比 ,(1)切断海马伞 -穹隆通路明显延缓了大鼠运动平衡能力的恢复 ;(2 )切断海马伞 -穹隆通路后 ,银杏类黄酮 (FGb)失去了促进脑挫伤后运动平衡能力恢复的作用 ;(3)原位杂交显示 ,脑损伤后海马DG (齿状回 )和CA3区中生长相关蛋白 (GAP 4 3)mRNA的水平明显提高 ;(4)FGb促进脑损伤后海马DG和CA3区中的GAP 4 3mRNA水平的上调。这些信息提示 ,海马参与脑硬性挫伤后的运动代偿 。

GAP 43 mRNA (growth associated protein 43 mRNA) is one of the idios yncratic neuroprotein of mammals. It can facilitate the growth and regenesis of synapse in the development and lesion of neural system. It has been proved that t he level of GAP 43 mRNA raised during the process of synapses regenesis induc ed by the lesion of center neural system. In order to study the role of hippocampu s in the neuroplasticity, we established the model of one side injurying the lo c omotive cortex of rats cerebrum which can induce hemiplegia by impact of heavy object and observed the influence of hippocampu lesion and FGb(flavonoid of G inkgo biloba ) fed on the recovery of locomotive equilibrium ability after TB I. We also used the hybridization in situ to examine the level of GAP 43 mRNA in DG (d entate gyrus) and CA3 region of hippocampus and the effects of FGb in the compen sation of locomotive equilibrium ability after TBI. We observed the influence o f hippocampus on behaviour recovery following cortex impact injury with the meth od of rotational beam and hybridization in situ in rats. 64 Wistar male rat s(we ight: 160±20 g) was used and separated into two groups. One group (28 rats) was watched in behavior recovery. We took the rats speed of passing the rotationa l beam as a representation of locomotive equilibrium ability, studied the behaiv or compentation after TBI, and also the influence of hippocampus and the effect of FGb in further. The other group (36 rats) was used to study the change of GAP 43 mRNAs level in the DG and CA3 region of hippocampus in process of behavior r ecovery with or without FGb fed. The results showed that: (1)the recovery of l o comotive equilibrium ability was remarkably impeded after transsection of fimbri a fornix in rats following TBI; (2) after transsection of fimbria fornix, FGb co uld not facilitate the recovery of locomotive equilibrium ability after TBI; (3 ) the results of hybridization in situ showed that the level of GAP 43 mRNA in th e DG and CA3 region of hippocampus rised remarkably after TBI; (4) FGb improved the raised level of GAP 43 mRNA in DG and CA3 region of hippocampus after TBI. T hese results suggest that hippocampus is involved in the porcess of recovery of locomotive equilibrium ability after TBI, and also plays a role in the facilitat ed effect of FGb on the recovery of locomotive equilibrium ability after TBI. Al l the information suggested that hippocampus is a pivotal brain region in the be havior compensation which is a re adaptation and re learning process after TBI .