中国神经再生研究(英文版) ›› 2016, Vol. 11 ›› Issue (7): 1185-1190.doi: 10.4103/1673-5374.187065

• 原著:视神经损伤修复保护与再生 • 上一篇    下一篇

锰离子增强磁共振活体示踪视神经成像的量效和时效反应

  

  • 出版日期:2016-07-30 发布日期:2016-07-30
  • 基金资助:
    973项目(2011CB707506);北京大学第三医院重点项目(YZZ08-9-13);北京大学第三医院Linghu基金(64508-01)

Dose response and time course of manganese-enhanced magnetic resonance imaging for visual pathway tracing in vivo

Wei-ling Wang1, 2, Hui Xu3, Ying Li4, Zhi-zhong Ma4, Xiao-dong Sun5, *, Yun-tao Hu1, 4, *   

  1. 1 Department of Ophthalmology, Beijing Tsinghua Changgung Hospital, Tsinghua University Medical Center, Beijing, China 2 Department of Ophthalmology, General Hospital of Ningxia Medical University, Yinchuan, Ningxia Hui Autonomous Region, China 3 Department of Radiology, Peking University Third Hospital, Beijing, China 4 Peking University Eye Center, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing, China 5 Department of Ophthalmology, Shanghai Jiao Tong University Affiliated First People’s Hospital, Shanghai, China
  • Online:2016-07-30 Published:2016-07-30
  • Contact: Yun-tao Hu or Xiao-dong Sun, ythu@mail.tsinghua.edu.cn or xdsun@sjtu.edu.cn.
  • Supported by:
    This study was supported by a grant from the National Basic Research Program of China (973 Program), No. 2011CB707506; the Seed Fund from the Peking University Third Hospital of China, No. YZZ08-9-13; and the Linghu Fund from the Peking University Third Hospital of China, No. 64508-01.

摘要:

轴索示踪可以有效检测视神经的损伤和再生,但既往采用的组织学方法不能观察到神经轴浆流和突触传递动态过程。锰离子增强磁共振成像(MEMRI)可有效进行活体视神经示踪。作者实验中将不同浓度的MnCl2注射至兔左眼玻璃体,注射后MRI观察应用不同时间后兔视觉通路的成像发生了变化。结果发现2 mM的MnCl2即可使视神经显像增强,但外侧膝状体和上丘脑的图像没有变化,而5-40mM的MnCl2可使视网膜投射到对侧上丘的视觉通路的信号显著增强,但2-40 mM的MnCl2都没能使大脑视觉皮质中的信号增强。注射MnCl2后24h图像增强最为显著,而24h-7d时信号逐渐减弱。由结果可知,锰离子增强磁共振图像是活体示踪视神经的一种可行方法,信号强度与Mn2+玻璃体腔注射的剂量有关,且最强的信号出现在玻璃体内注射后24 h。

orcid: 0000-0003-4663-0684 (Yun-tao Hu)

关键词: 神经再生, 锰, 磁共振成像, 视觉通路, 视神经, 示踪, 体内, 玻璃体腔注射, 量效, 时效

Abstract: Axonal tracing is useful for detecting optic nerve injury and regeneration, but many commonly used methods cannot be used to observe axoplasmic flow and synaptic transmission in vivo. Manganese (Mn2+)-enhanced magnetic resonance imaging (MEMRI) can be used for in vivo longitudinal tracing of the visual pathway. Here, we explored the dose response and time course of an intravitreal injection of MnCl2 for tracing the visual pathway in rabbits in vivo using MEMRI. We found that 2 mM MnCl2 enhanced images of the optic nerve but not the lateral geniculate body or superior colliculus, whereas at all other doses tested (5–40 mM), images of the visual pathway from the retina to the contralateral superior colliculus were significantly enhanced. The images were brightest at 24 hours, and then decreased in brightness until the end of the experiment (7 days). No signal enhancement was observed in the visual cortex at any concentration of MnCl2. These results suggest that MEMRI is a viable method for temporospatial tracing of the visual pathway in vivo. Signal enhancement in MEMRI depends on the dose of MnCl2, and the strongest signals appear 24 hours after intravitreal injection.

Key words: nerve regeneration, manganese, magnetic resonance imaging, visual pathway, optic nerve, tracing, in vivo, intravitreal injection, time, dose, neural regeneration