【目的】研究血液通路在H5N1高致病性禽流感病毒入侵小鼠中枢神经系统中的作用。【方法】用3株H5N1病毒滴鼻感染BALB/c小鼠,研究小鼠肺、脑、血中的病毒在感染后不同时间点的复制动态及病理进展,通过免疫组化和免疫荧光染色显示病毒在脑部血管内皮细胞及血管周围神经组织的感染情况。【结果】小鼠感染后病毒迅速在肺中高效复制,随即形成病毒血症;感染后第6天病毒在肺中的滴度和在血液样本中的检出率达到峰值,此时小鼠脑部才开始检测到病毒;小鼠脑内血管内皮细胞、脑血管周围神经组织的神经元和神经胶质细胞中可检测到流感病毒NP蛋白。【结论】血液播散可能是高致病性H5N1禽流感病毒进入中枢神经系统的途径之一。 【Objective】 To investigate the role of blood pathway in the invasion of mouse central nervous system by H5N1 HPAI virus. 【Method】 BALB / c mice were infected intranasally with three strains of H5N1 virus in order to study the replication dynamics and pathological changes of the virus in lung, brain and blood at different time points after infection. Immunohistochemistry and immunofluorescence staining Virus in the brain vascular endothelial cells and peripheral vascular tissue infection. 【Results】 The virus was rapidly and efficiently replicated in the lungs of mice after infection, and then viremia was formed. On the 6th day after infection, the titer of the virus in the lung and the detection rate in the blood samples reached a peak. At this time, the mouse brain Department began to detect the virus; mouse brain vascular endothelial cells, cerebrovascular peripheral nerve tissue neurons and glial cells can detect influenza virus NP protein. 【Conclusion】 Hematogenous dissemination may be one of the pathways to enter the central nervous system of highly pathogenic H5N1 avian influenza virus.