Department of Radiology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, 610041, China.
Department of Biomedical Engineering, College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, 310030, China.
Neurochem Res. 2022 Apr;47(4):979-1000. doi: 10.1007/s11064-021-03498-5. Epub 2022 Jan 4.
Prolonged exposure to high altitudes above 2500 m above sea level (a.s.l.) can cause cognitive and behavioral dysfunctions. Herein, we sought to investigate the effects of chronic exposure to plateau hypoxia on the hippocampus in a rat model by using voxel-based morphometry, creatine chemical exchange saturation transfer (CrCEST) and dynamic contrast-enhanced MR imaging techniques. 58 healthy 4-week-old male rats were randomized into plateau hypoxia rats (H group) as the experimental group and plain rats (P group) as the control group. H group rats were transported from Chengdu (500 m a.s.l.), a city in a plateau located in southwestern China, to the Qinghai-Tibet Plateau (4250 m a.s.l.), Yushu, China, and then fed for 8 months there, while P group rats were fed in Chengdu (500 m a.s.l.), China. After 8 months of exposure to plateau hypoxia, open-field and elevated plus maze tests revealed that the anxiety-like behavior of the H group rats was more serious than that of the P group rats, and the Morris water maze test revealed impaired spatial memory function in the H group rats. Multimodal MR imaging analysis revealed a decreased volume of the regional gray matter, lower CrCEST contrast and higher transport coefficient Ktrans in the hippocampus compared with the P group rats. Further correlation analysis found associations of quantitative MRI parameters of the hippocampus with the behavioral performance of H group rats. In this study, we validated the viability of using noninvasive multimodal MR imaging techniques to evaluate the effects of chronic exposure to a plateau hypoxic environment on the hippocampus.
长期暴露于海拔 2500 米以上的高海拔地区可能会导致认知和行为功能障碍。在此,我们通过体素形态计量学、肌酸化学交换饱和传递(CrCEST)和动态对比增强磁共振成像技术,研究了慢性高原低氧暴露对大鼠海马的影响。将 58 只 4 周龄雄性大鼠随机分为高原低氧组(H 组)作为实验组和平原组(P 组)作为对照组。H 组大鼠从中国西南部高原城市成都(海拔 500 米)运至海拔 4250 米的青海玉树,然后在那里饲养 8 个月,而 P 组大鼠则在成都(海拔 500 米)饲养。经过 8 个月的高原低氧暴露,旷场和高架十字迷宫测试显示 H 组大鼠的焦虑样行为比 P 组大鼠更严重,而 Morris 水迷宫测试显示 H 组大鼠的空间记忆功能受损。多模态磁共振成像分析显示,与 P 组大鼠相比,H 组大鼠海马区的局部灰质体积减小,CrCEST 对比降低,转运系数 Ktrans 升高。进一步的相关性分析发现,海马的定量 MRI 参数与 H 组大鼠的行为表现相关。在这项研究中,我们验证了使用非侵入性多模态磁共振成像技术评估慢性高原低氧环境对海马影响的可行性。