Changes in myelin basic protein expression in the hippocampus and prefrontal cortex of model mice with post-traumatic stress disorder
10.3760/cma.j.cn371468-20241011-00474
- VernacularTitle:创伤后应激障碍模型小鼠海马和前额叶皮质髓鞘碱性蛋白表达变化
- Author:
Jixin LI
1
;
Min HU
;
Yuanyuan HU
;
Yao MENG
;
Guiqing ZHANG
Author Information
1. 石河子大学第一附属医院临床心理科，石河子 832008
- Publication Type:Journal Article
- Keywords:
Post-traumatic stress disorder;
Myelin basic protein;
Hippocampus;
Prefrontal cortex;
Mouse
- From:
Chinese Journal of Behavioral Medicine and Brain Science
2025;34(2):97-103
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate changes in behavior and hippocampal and prefrontal cortical myelin basic protein(MBP) in model mice with post-traumatic stress disorder(PTSD).Methods:Thirty-two clean-grade male C57BL/6J mice were randomly divided into control group, PTSD 3 d group, PTSD 7 d group and PTSD 14 d group based on matching body mass, with 8 mice in each group. The mice in PTSD 3 d, 7 d and 14 d groups were decapitated at 3 d, 7 d, and 14 d after modeling.The PTSD mouse model was established through conditioned foot shock and single prolonged stress. Anxious- and depressive-like behaviors of mice were assessed by the open field test(OFT). The mouse step-through passive avoidance experiment was used for electric shock training and learning and memory retention. Myelin morphology alterations in the hippocampus and prefrontal cortex of the mouse were examined via myelin staining.The expression levels of MBP were quantified using Western blot and immunohistochemical staining techniques. All experimental data were analyzed and visualized using GraphPad Prism 8.0.2 and SPSS 25.0, the multi groups comparison of behavioral and molecular indicator data was conducted by one-way ANOVA, and the correlation between MBP relative protein expression level and behavioral indicators was analyzed by Pearson correlation analysis.Results:(1) Behavioral results: in OFT, there were significant differences in total distance, average speed, time of stationary and times of entering the central area among all groups( F=16.72, 16.74, 7.37, 5.93, all P<0.05).The total distance and the average speed time of PTSD 3 d, 7 d, 14 d group were all lower than those in control group(all P<0.05).In the mouse step-through passive avoidance experiment, significant differences were observed across all groups in terms of total distance traveled, average speed, dark box entries, and activity time( F=52.78, 55.47, 9.07, 24.88, all P<0.05).All the indexes of PTSD 3 d group and PTSD 7 d group were all higher than those in control group and PTSD 14 d group(all P<0.05).(2)Myelin staining revealed statistically significant differences in the myelin staining areas of the hippocampal CA1 region and the prefrontal cortex across all groups( F=6.67, 5.77, all P<0.05). The stained myelin area in the CA1 region of the hippocampus in the PTSD 3 d group((123.30±11.62)μm 2)was significantly lower compared to the control group((153.00±2.61)μm 2)( P<0.05). The stained myelin area in the prefrontal cortex of the PTSD 3 d group((119.50±9.26)μm 2)was significantly lower compared to that in the control group((154.80±12.40)μm 2)( P<0.05). (3) Western blot results demonstrated significant variations in the expression levels of myelin basic protein (MBP) within the hippocampus and prefrontal cortex across all experimental groups ( F=10.15, 5.28, all P<0.05). The expression levels of MBP in the hippocampal tissue of the PTSD 3 d group (0.89±0.07), PTSD 7 d group (0.90±0.14), and PTSD 14 d group (0.85±0.13) were significantly lower compared to those in the control group(1.17±0.02)(all P<0.05). The expression levels of MBP protein in the prefrontal cortex of the PTSD 3 d group(0.73±0.16) and PTSD 7 d group (0.70±0.12)were significantly lower compared to those in the control group (0.94±0.04)(all P<0.05). (4) Immunohistochemical staining revealed significant variations in the number of MBP-positive cells within the hippocampal CA1 region and the prefrontal cortex across all groups ( F=39.32, 21.81, both P<0.05). The quantity of MBP-positive cells in the hippocampal tissue of mice in the PTSD 3 d group((187.10±1.12)/mm 2)and PTSD 7 d group((193.10±2.18) /mm 2)was significantly reduced compared to the control group((204.80±3.25)/mm 2)(all P<0.05). The quantity of MBP-positive cells in the prefrontal cortex of the PTSD 7 d group((183.90±1.71)/mm 2) was significantly reduced compared to the control group((191.60±1.04) /mm 2)( P<0.05). Conclusion:The PTSD model mice showed anxious- and depression-like behavior, impaired learning and memory ability, and myelin damage in the hippocampus and prefrontal cortex.
