Objective: To explore the effect of simulated gas of thermobaric bomb charge explosion on cognitive function and the related mechanism of damage. Methods: In January 2022, thirty-two SPF rats were selected and randomly divided into control group, exposed group 1, 2 and 3 (the exposure time of the simulated gas of the explosion of the thermobaric bomb charge was 5 min, 10 min and 15 min, respectively) according to random number table method, with 8 rats in each group. The simulated gas of the explosion of the thermobaric bomb charge were CO 0.15%, CO(2) 3%, NO 0.1%, O(2) 15%, and the rest were N(2). After 30 days of exposure, water maze was used to detect the learning and memory function of rats. Golgi staining was used to observe the number distribution and morphological structure of hippocampal neurons in rats. Western blot was used to detect the expression of Tau-5, pSer262, pSer396, pThr181 and pThr231 proteins in rats. Repeated measure ANOVA was used to compare the design data of repeated measure, one-way ANOVA was used for multi-group mean comparison, and LSD method was used for pound-wise comparison. Results: There were significant differences in the results of repeated measurement ANOVA of the water maze localization navigation test (F=80.98, P<0.001), and there was an interaction between the group and the training days (F=2.16, P=0.022). There were significant differences in escape latency of rats at the 2nd, 3rd, 4th and 5th days among all groups (P<0.05). The results of spatial exploration showed that the frequency of rats crossing the platform was significantly different among all groups (F=4.49, P=0.011). The frequency of rats crossing the platform in exposed group 2 and exposed group 3 was lower than that in control group, and the frequency of rats crossing the platform in exposed group 3 was lower than that in exposed group 1 (P<0.05). With the increase of exposure time, the number of hippocampal neurons decreased, and the dendrite spine density of neurons in CA1 region decreased (P<0.05). Compared with the control group, there was no significant difference in the relative expression level of Tau-5 protein in all exposed groups (P>0.05), but the expression level of pSer262 protein was significantly increased (P<0.05). Compared with the control group, the protein expressions of pSer396, pThr181 and pThr231 in exposed group 2 and exposed group 3 were significantly increased (P<0.05) . Conclusion: The simulated gas of the explosion of the thermobaric bomb charge may contribute to the development of cognitive dysfunction by damaging hippocampal neurons with aberrant phosphorylation of Tau proteins.
目的： 探究温压装药爆炸模拟气体对认知功能的影响及其损伤的相关机制。 方法： 于2022年1月，将32只SPF级雄性SD大鼠按随机数字表法随机分为对照组、暴露组1、2、3（温压装药爆炸模拟气体暴露时间分别为5、10、15 min），每组8只。温压装药爆炸模拟气体组分包括CO 0.15%、CO(2) 3%、NO 0.1%、O(2) 15%，其余为N(2)。暴露结束30 d后，水迷宫检测大鼠学习记忆功能，高尔基染色观察大鼠海马神经元分布及形态结构，蛋白免疫印迹法检测大鼠Tau-5、pSer262、pSer396、pThr181、pThr231蛋白表达量。采用重复测量方差分析比较重复测量设计资料，多组均数比较采用单因素方差分析，两两比较采用LSD法。 结果： 水迷宫定位航行实验重复测量方差分析结果差异有统计学意义（F=80.98，P<0.001），并且组别与训练天数之间存在交互作用（F=2.16，P=0.022）。各组大鼠第2、3、4、5天的逃避潜伏期差异均有统计学意义（P<0.05）。空间探索结果显示，各组大鼠穿越平台次数差异有统计学意义（F=4.49，P=0.011），暴露组2、暴露组3穿越平台次数低于对照组，且暴露组3穿越平台次数低于暴露组1（P<0.05）。随暴露时间的增加，大鼠海马神经元数量减少，CA1区神经元树突棘密度降低（P<0.05）。与对照组比较，各暴露组Tau-5蛋白相对表达量差异无统计学意义（P>0.05），pSer262蛋白表达量明显上升（P<0.05）；与对照组比较，暴露组2、暴露组3的pSer396、pThr181、pThr231蛋白表达量均明显上升（P<0.05）。 结论： 温压装药爆炸模拟气体暴露可能通过损伤海马神经元和Tau蛋白异常磷酸化，导致认知功能障碍的发生。.
Keywords: Cognitive dysfunction; Neurons; Rats; Tau proteins; Thermobaric bomb charge.