控制性脑皮质撞击致不同损伤程度颅脑创伤大鼠模型的建立

目的 应用控制性脑皮质撞击仪（CCI）建立不同损伤程度的颅脑创伤（TBI）大鼠模型,为探索TBI病理生理进程提供实验依据.方法 40只雄性Wistar大鼠按数字表随机分为4组（3组实验组、1组假手术组）,每组10只.应用电子控制性皮质撞击仪（eCCI-6.3）,设定不同打击参数,对大鼠顶叶大脑皮质区进行精确撞击.其中,实验组打击速率分别为4 m/s、5m/s、6m/s,打击时间均为200 ms,打击深度均为2 mm.假手术组仅开骨窗不行撞击.致伤24 h后采用神经功能缺陷评分（NSS）观察大鼠行为学改变,应用多普勒流量计测定大鼠脑损伤周围区域局部脑血流（rCBF）.致伤48 h后处死大鼠,取脑组织行甲苯胺蓝染色观察脑组织缺损程度,HE染色评估脑组织病理学改变,透射电镜观察神经细胞超微结构.结果 大鼠脑损伤程度与打击强度相关,打击速率4m/s模拟轻度TBI、5m/s模拟中度TBI、6m/s模拟重度TBI.与假手术组比较,TBI各组大鼠神经功能受损,局部脑血流量降低（均P＜0.01）,脑组织神经元皱缩、细胞周围空泡、线粒体结构异常,而且损伤程度随打击速率增强而递增,组间差异有统计学意义（P＜0.05）.结论 应用eCCI脑皮质撞击仪成功建立TBI大鼠模型,通过调整打击速率给予轻度、中度和重度TBI分级,为进一步研究TBI病理生理机制提供了一种精确有效的TBI动物模型制作方法.

The establishment of the controlled cortical impact-induced traumatic brain injury model with different severity in rats

Objective To establish the electric controlled cortical impact （eCCI）-induced traumatic brain injury （TBI） model in rats with different severity in degree,which may serve as a suitable platform to provide experimental evidence for the pathophysiological following TBI.Methods A total of 40 male Wistar rats were randomly divided into 3 experimental groups and sham group.TBI rats （n=10/group） were positioned beneath the controlled cortical impactor device （eCCI） and subjected to impact injury at 2 mm depth of penetration,for a sustained depression of 200 ms,at 4 m/s,5 m/s,6 m/s velocity for mild,moderate,and severe TBI,respectively.Sham-operated rats （n=10） underwent identical surgical procedures,including craniotomy,without receiving the cortical impact.Neurological function and regional cerebral flow （24 h after CCI）,contusion volume,histopathological,and ultrastructural changes （48 h after CCI） were measured,respectively.Results The severity of the pathological changes in rats was increased as the injury aggravated.The eCCI device impacted the brain at 4 m/s,5 m/s,6 m/s velocity for mild,moderate,and severe TBI,respectively.TBI groups showed impaired neurological function,and decreased rCBF lower than that of sham-operated group （all P〈0.01）.Furthermore,neuronal pathological abnormalities in TBI groups,including neuron shrinking,perineuronal vacuole,and structural abnormalities of mitochondria.Increased severity of injury was apparent following the increased level of the impacted velocity,and significant differences were observed between TBI groups （P〈0.05）.Conclusion The TBI animal model with mild,moderate,and severe brain injury can be established successfully by 4 m/s,5 m/s,and 6 m/s of impact velocity respectively with the eCCI-6.3 device.The novel eCCI-induced TBI model in rats possibly serves as a novel useful approach in the development of TBI models.