Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice  

作　　者：Jiao Mu Liufang Hao Zijue Wang Xuyang Fu Yusen Li Fei Hao Hongmei Duan Zhaoyang Yang Xiaoguang Li 

机构地区：[1]Beijing Key Laboratory for Biomaterials and Neural Regeneration,School of Biological Science and Medical Engineering,Beihang University,Beijing,China [2]Department of Neurobiology,School of Basic Medical Sciences,Capital Medical University,Beijing,China

出　　处：《Neural Regeneration Research》2024年第3期636-641,共6页中国神经再生研究（英文版）

基　　金：supported by the National Natural Science Foundation of China,Nos.31 730030 (to XL),81941011 (to XL),31 771053 (to HD),82271403 (to XL),82272171 (to ZY),31971279 (to ZY);82201542 (to FH);the Natural Science Foundation of Beijing,No.7222004 (to HD);the Science and Technology Program of Beijing,No.Z181100001818007(to ZY)

摘　　要：Stroke can cause Wallerian degeneration in regions outside of the brain,particularly in the corticospinal tract.To investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke,we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal tract.We first used a routine,sensitive marker of axonal injury,amyloid precursor protein,to examine Wallerian degeneration of the corticospinal tract.An antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex,with no positive signal in distal parts of the corticospinal tract,at all time points.To improve visualization of Wallerian degeneration,we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing axons.Using this approach,we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after stroke.In addition,microglia mobilized and activated early,from day 7 after stroke,but did not maintain a phagocytic state over time.Meanwhile,astrocytes showed relatively delayed mobilization and a moderate response to Wallerian degeneration.Moreover,no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal tract.In conclusion,our data provide evidence for dynamic,pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.

关 键 词：corticospinal tract green fluorescent protein MICROGLIA spinal anterior horn cells stroke virus trace Wallerian degeneration 

分 类 号：R743.3[医药卫生—神经病学与精神病学]