实验性恒河猴脊髓半横切损伤模型的建立

The lateral hemisection of cervical spinal cord injury model in rhesus monkey

目的通过脊髓半侧横切的方法建立灵长类恒河猴脊髓半横切损伤动物模型,用于神经再生的研究。方法 5只成年恒河猴称重麻醉后,颈部后正中切口显露C3-5脊髓,于C4用虹膜刀切开脊髓左半侧0．5cm,通过体感诱发电位(somatosensory evoked potential SSEP)监测,确保波形改变并观察恒河猴术后24h、7d肢体运动功能和SSEP变化。结果术后24h、7d同侧肢体瘫痪,肢体运动评分由术前的5分降到1分,SSEP显示术前潜伏期(15．88±2．53)毫秒,术后24h(22．26±4．12)毫秒;7d(23．12±3．92)毫秒延长明显(P<0．01),波幅术前(11．92±5．48)μV,术后24h(5．34±3．04) μV,7d(5．78±2．98)μV,降低明显(P<0．01)。结论恒河猴麻醉后用虹膜刀脊髓半横切能损伤皮质脊髓束,引起肢体瘫痪,结果稳定可靠,操作较为简便,可建立脊髓半侧横切损伤动物模型,重复性较好,为脊髓损伤的神经修复实验研究提供了模型基础。

Objective To establish an animal model of spinal cord injury by lateral hemisection of cervical spinal cord in rhesus monkey for studying regeneration of spinal cord. Methods Adult rhesus monkeys will be weighed and anesthetized（ n = 5,4000 -4500g）. Through a dorsal midline incision in the neck, the C3-5 will be exposed, then C4 lamineetomy procedure performed. By using the artery as the medial boundary, the left hemispinal cord （cortical spinal tract） will be transected with a knife, creating a lesion of the medulla. During the operation, the somatosensory evoked potentials will be monitored. Behavioral testing will be performed before surgery; on 24 hours, 7days after surgery. Results The somatosensory evoked potentials mean latency is （15.88±2.53 ） ms at left side and the mean amplitude is（ 11.92±5.48 ）μV. The latency is significantly delayed to be （22.26±4.12）ms and（23.12±3.92）ms respectively in 24hr and 7d after the operation. The amplitude significantly depressed （5.34±3.04）μV and（ 5.78±2.98 ）μV respectively. The left side muscle strength become weaker significantly from grade 5 to grade 1 after the operation. Conclusions Lateral hemisection of cervical spinal cord to establish an animal model is effective and accurate. It has stable and repetitive characters for research on spinal cord injury.