构建一种创伤性闭合性中型颅脑损伤（TBI）动物模型。

雄性SD大鼠80只，完全随机平均分为4组，每组20只，包括3组不同程度的TBI（A、B、C）组和假手术（N）组。参照Marmarou损伤模型，A、B、C组分别按拟定的打击高度（1.0、1.5、2.0 m）使重量为450 g的钢棒自由下落撞击大鼠头部建立TBI。观察各组大鼠伤后一般状况、神经行为学、脑组织形态学等改变。

伤后14 d内，N、A、B、C组死亡率分别为0%、5%、20%、60%，随着致伤量的增加，死亡率增加（P<0.05），伤后各观察时间点神经功能缺损评分（mNSS）升高（P<0.05），均高于N组，差异均具有统计学意义。HE染色结果提示，与N组比较，随着致伤量的增加，光镜下可见基质疏松、神经元细胞周围间隙和血管间隙增宽、神经元细胞排列紊乱且变性、神经胶质肿胀变性程度更加明显。免疫组织化学染色结果提示，与N组比较，A、B、C组大脑皮质β-APP、NF-L阳性表达程度增强。

以450 g的钢棒自1.5 m高处自由打击大鼠颅骨可成功建立创伤性闭合性中型颅脑损伤动物模型，其病理学特征明显，重复性和稳定性好。

To establish the closed moderate traumatic brain injury animal model.

Eighty male SD rats were randomly divided into 4 groups, 20 in each group, including three groups with different degrees of brain injury (A, B, C) and sham operation (N). Referring to Marmarou injury model, group A, B and C made the steel bar weighing 450 g fall freely and hit the rat head to establish TBI according to the designed strike height (1.0, 1.5, 2.0 m). The general condition, neurobehavioral and brain histomorphological changes were observed.

Within 14 d after injury, the mortality rates of group N, A, B and C were 0%, 5%, 20% and 60%, respectively. With the increase of the amount of injury, the mortality rate increased (P<0.05). With the increase of the number of injuries, the neurological deficit score (mNSS) increased at each time point after injury (P<0.05), which was higher than that in group N. The results of HE staining showed that, compared with group N, with the increase of wound volume, HE staining showed matrix loosening, widening of pericellular space and vascular space of neurons, disordered arrangement and degeneration of neurons and swelling and degeneration of glia were more obvious under light microscope. The results of immunohistochemical staining showed that the positive expression of β-APP and NF-L in cerebral cortex of group A, B and C was higher than that of group N.

The steel bar weighted 450 g felled from the height of 1.5 m that hit against the middle of head of rat have established a relatively stable moderate closed TBI animal model with obviously pathological features changes and more stable and repeatable than other groups.