Dose response and time course of manganeseenhanced magnetic resonance imaging for visual pathway tracing in vivo  

作　　者：Wei-ling Wang Hui Xu Ying Li Zhi-zhong Ma Xiao-dong Sun Yun-tao Hu 

机构地区：[1]Department of Ophthalmology,Beijing Tsinghua Changgung Hospital,Tsinghua University Medical Center [2]Department of Ophthalmology,General Hospital of Ningxia Medical University [3]Department of Radiology,Peking University Third Hospital [4]Peking University Eye Center,Peking University Third Hospital,Key Laboratory of Vision Loss and Restoration,Ministry of Education [5]Department of Ophthalmology,Shanghai Jiao Tong University Affiliated First People's Hospital

出　　处：《Neural Regeneration Research》2016年第7期1185-1190,共6页中国神经再生研究（英文版）

基　　金：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;the Linghu Fund from the Peking University Third Hospital of China,No.64508-01

摘　　要：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（Mn^2＋）-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 Mn Cl2 for tracing the visual pathway in rabbits in vivo using MEMRI.We found that 2 m M Mn Cl2 enhanced images of the optic nerve but not the lateral geniculate body or superior colliculus,whereas at all other doses tested（5–40 m M）,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 Mn Cl2.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 Mn Cl2,and the strongest signals appear 24 hours after intravitreal injection.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（Mn^2＋）-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 Mn Cl2 for tracing the visual pathway in rabbits in vivo using MEMRI.We found that 2 m M Mn Cl2 enhanced images of the optic nerve but not the lateral geniculate body or superior colliculus,whereas at all other doses tested（5–40 m M）,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 Mn Cl2.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 Mn Cl2,and the strongest signals appear 24 hours after intravitreal injection.

关 键 词：tracing detecting optic brightness retina viable synaptic until cortex fitting 

分 类 号：R445.2[医药卫生—影像医学与核医学] R774.6[医药卫生—诊断学]