Wang Peng, Song Xuewei, Wang Qiushi, Qiu Jinlong, Zhu Xiyan, Yu Tianming, Xiang Hongyi, Zhao Hui
State Key Laboratory of Automotive Simulation and Control, College of Automotive Engineering, Jilin University, Changchun, Jilin, China.
Institute for Traffic Medicine, Daping Hospital, Army Medical University, Chongqing, China.
Sci Rep. 2025 May 10;15(1):16293. doi: 10.1038/s41598-025-00108-0.
Memory dysfunction, a common symptom following closed head impact injuries, suggests deficits in hippocampal function. This defect is thought to be related to impact strength and individual animal weight. In this study, head impact experiments were performed on male Sprague Dawley rats to establish a quantitative relationship between impact strength, body weight and hippocampal injury. A two-factor, three-level experimental design was established using the L(3) orthogonal table, with impact strength and body weight as the variables. According to the protocol, rats were injured using a BIM-IV animal impact machine, and the effects of impact strength and body weight factors on hippocampal injury were evaluated by the results of Morris water maze and hematoxylin-eosin staining of the hippocampus at 24 h post-injury. Using the percentage of cell loss in the hippocampus as an indicator, quadratic regression models were established to describe the effects of impact strength and body weight on cell loss in the CA1, CA3, and DG regions of the hippocampus. The results revealed a quadratic, non-linear relationship between impact strength, body weight and the percentage of cell loss in these regions. Specifically, increasing impact strength resulted in a higher proportion of cell loss, whereas increasing body weight was associated with a reduction in cell loss. Consistent with these pathological findings, higher impact strength prolonged the time required for rats to locate the hidden platform in the Morris water maze, while higher body weight shortened the platform-finding time under the same impact strength. The quadratic orthogonal regression equations for hippocampal injury as a function of mechanical load and body weight provide valuable insights for predicting hippocampal damage and understanding its underlying mechanisms.
记忆功能障碍是闭合性头部撞击伤后的常见症状，提示海马功能存在缺陷。这种缺陷被认为与撞击强度和动物个体体重有关。在本研究中，对雄性Sprague Dawley大鼠进行头部撞击实验，以建立撞击强度、体重与海马损伤之间的定量关系。使用L(3)正交表建立了一个双因素、三水平的实验设计，将撞击强度和体重作为变量。根据实验方案，使用BIM-IV动物撞击机对大鼠造成损伤，并通过Morris水迷宫实验结果以及损伤后24小时海马的苏木精-伊红染色来评估撞击强度和体重因素对海马损伤的影响。以海马细胞丢失百分比为指标，建立二次回归模型来描述撞击强度和体重对海马CA1、CA3和DG区细胞丢失的影响。结果显示，撞击强度、体重与这些区域的细胞丢失百分比之间存在二次非线性关系。具体而言，撞击强度增加导致细胞丢失比例更高，而体重增加与细胞丢失减少相关。与这些病理结果一致，较高的撞击强度延长了大鼠在Morris水迷宫中找到隐藏平台所需的时间，而在相同撞击强度下，较高的体重缩短了找到平台的时间。作为机械负荷和体重函数的海马损伤二次正交回归方程为预测海马损伤及其潜在机制提供了有价值的见解。
