猴脊髓半横断模型的制作及后肢功能评价

Evaluation of Neurological Function Following Establishment of Spinal Cord Hemisection Model in Rhesus

目的 建立恒河猴半横断脊髓损伤模型,观察脊髓形态及神经功能改变。方法 动物分为半横断组和假手术组,椎板切开横断左侧脊髓,采用改良Tarlov评分及皮层体感诱发电位(CSEP)评价神经功能,同时行HE染色组织学观察,计数脊髓前角神经元数。结果 术后3个月时,脊髓半横断切口处形成不规则的空腔,内有少许组织充填,脊髓灰质前角神经元计数,半横断下端伤侧较对侧减少,但后肢功能在伤后14 d至3月有一定程度的渐进性恢复。结论 建立脊髓半横断模型,横断侧后肢神经功能有一定程度代偿恢复,提示脊髓半横断伤后有一定功能可塑性。

Objective To establish spinal cord half-transection model in rhesus and investigate the neurological function and morphologic changes following spinal cord hemisection in rhesus. Methods Four cynomolgus monkeys were subjected to T-11 laminectomy and resection of a 1-mm length of hemispinal cord, while the controls underwent the identical laminectomy procedure but not the half-transection of the spinal cord. Neurological function of hindlimb was evaluated using modified Tarlov' grading, and cortical somatosensary evoked potentials(CSEP) were recorded in the 3rd postoperative month after spinal cord injury (SCI). The animals were sacrificed for histological examination. All the slices were processed with H-E staining and the number of neurons in the anterior horn of grey matter was counted. Results Irregular cavity was observed at the lesion site in the 3rd postoperative month. Distinct handicap of locomotor function in hindlimbs was observed in the half-transaction group immediately after SCI. As time went on, the locomotor function improved partially. Partial recovery of hindlimb function of adult monkey was noted in half-transection group from 14 days to 3 months after SCI, compared with that seen 24 hours postoperatively. The total number of neurons in the anterior horn of grey matter identical with hemitransection side was significantly smaller than that of the other side in the same segment (P<0.05). Conclusion A reproducible model of SCI in the nonhuman primate was established. Spontaneous partial recovery of the ipsilateral hindlimb function occurred in the monkey with spinal cord hemisected during different periods, which indicated the functional plasticity in the spinal cord after hemisection injury.