小鼠脑皮质撞击模型的构建和评估

The establishment and evaluation of the cortical impact injury model in the mouse

目的 ;探索建立小鼠脑皮质撞击模型,为今后进一步开展小鼠颅脑创伤研究创造条件。方法雄性C57BL/6J小鼠36只,随机分为6组（包括实验组5组和对照组1组）,应用NYU Impactor Ⅰ型脑皮质撞击仪,金属杆（重10g）从不同高度落下垂直打击小鼠脑皮质造成损伤,建立小鼠脑皮质撞击模型。致伤后观察小鼠神经反射及意识恢复时间。伤后24 h处死小鼠,取海马CA2/3区脑组织行退变神经元Fluoro-Jade B组织荧光染色,通过立体细胞计数观察退变神经元数量变化。结果打击高度为10~40 mm时,损伤侧脑组织病理改变的严重程度逐级加重,与损伤程度存在较好的相关性;打击高度为10 mm时可近似模拟轻型颅脑损伤;打击高度为20~30 mm时近似模拟中型颅脑损伤;打击高度为40 mm时近似模拟重型颅脑损伤。结论应用NYU Impactor Ⅰ型脑皮质撞击仪可以成功地制作出所需的小鼠脑皮质撞击模型,具有重复性好、简便易用的特点,是较理想的小鼠致伤模型。

Objective To establish the cortical impact injury model in the mouse by using the type 1 NYU Impactor.We believe that the works would help to build on our experience in the future traumatic brain injury researches in the mouse.Methods A total of 36 male C57BL/6J mouse were divided into 6 groups and were named control（1 group）and TBI groups（5 groups）respectively.There were 6 animals in each group.The falling metal rod（10 grams） produced various injury levels by directly impacting the mouse cortex from the different heights of the falling weight.The duration of suppression of the neurological reflex and consciousness were used as an indicator of traumatic injury severity.Mouse were euthanized at 24 hrs after TBI and brains were processed and stained according to the Fluoro-Jade B Histofluorescence.Ipsilateral neuronal degeneration in the CA2/3 regions of the hippocampus were quantified using stereological techniques.Results At the height of 10~40 mm,the NYU impactor could produce different degree of injuries to the mice.The severity of the pathological changes in mice increased as the injury aggravated.It produced the mild injury at the height of 10mm,moderate injury at the height of 20~30mm and severe injury at the height of 40mm.Conclusion The type 1 NYU impactor can produce graded cortical impact injury to the mice.The model is simple,stable and suitable for the TBI research in the mouse.