小鼠颈脊髓半侧挫伤模型的建立及其组织学特点

目的　建立基于位移控制的C57/6J小鼠C5脊髓半侧挫伤模型，观察其脊髓组织学改变。 方法　C57BL/6小鼠在麻醉状态下行C5左侧椎板切除术，打击头（直径0.75 mm）对准C5左侧，由电磁伺服材料试验机驱动挫伤脊髓，设定打击位移0.9 mm，打击速度50 mm/s。损伤后1周脊髓标本取材，EC染色，作组织学定量分析。 结果　打击参数结果稳定性与重复性良好。打击位移、打击速度和打击力分别为（0.880±0.035）mm、（48.146±4.367）mm/s、（0.407±0.129）N，损伤中心的脊髓组织学表现为：伤侧脊髓有明显的出血及正常组织结构破坏，脊髓背侧束、脊髓后角和部分前角有破坏；健侧脊髓结构基本保持完整。计算损伤中心平面的残存灰质比例、残存白质比例及损伤面积比例分别为（19±7）%、（88±9）%及（28±4）%。 结论　本研究成功建立小鼠颈脊髓半侧挫伤模型，此模型具有重复性较好的力学参数，表现出典型的单侧颈脊髓损伤的组织学特征，可为脊髓损伤分子机制和治疗研究奠定基础。

A cervical spinal cord hemi-contusion injury model in mice and its histological characterization

Objective　To develop a hemi-contusive injury mice model of cervical spinal cord injury (SCI) with displacement control, and demonstrate unilateral cord tissue loss. Methods　Every C57BL/6 mouse was under anesthesia, and the left spinal cord of C5 was exposed. A 0.75-mm-in-diameter cylinder impactor was driven to strike the left of C5 cord 0.9 mm at 50 mm/s by an electromagnetic-servo material testing machine. Spinal cord samples of all mice were harvested 1 week after injury and processed for EC staining for quantitative analysis. Results　Average contusive displacement, speed and compressive force were (0.880±0.035) mm, (48.146±4.367) mm/s and (0.407±0.129) N respectively. Histological analysis showed that there were hematoma and tissue loss of ipsilateral dorsal funiculus, dorsal horn and partly ventral horns, while contralateral cord were intact. In epicenter, the average percentage of lesion area, spared white and gray matter area accounted for (19±7)%, (88±9)% and (28±4)% respectively.　Conclusions　This study establishes a cervical spinal cord hemi-contusion model in mice which achieves consistent biomechanical parameters, and results in typical ipsilateral spinal cord tissue loss. The present study can provide a SCI model for molecular mechanism and therapeutic research.