Ultrastructural Pathology of Nerve Cells in Mouse Brain Infected with Epidemic B Encephalitis Virus

An animal model of epidemic(Japanese)B encephalitis was estabilisged by injecting theJin Wei Yah 1 stain of B encephalitis virus into the peritoneal cavity of mice.The ultrastructuralchanges of the nerve cells in their brains were studied,special attention being paid to some types ofnerve cell in the cerebellar cortex.The infectet Purkinje cells and especially the granular cells showedspecial and inter,sting pathological features.These were compared with the changes found in the in-fected nerve cells in the cerebral cortex,diencephalon and mesencephalon.A radiating structure consisting of a microveside-microtubule aggregation body at the centerand endoplastic reticulum or virus replication multivesicular structures around it was often found in thein fected nerve cells.Its morphological features were described in detail,and its significance and the se-quenoe of events of its development discussed.In the late stage of infection,virus particles were found in the nuclei of part of the necroticcells.It is considered that they entered the nuclei from the cytoplasm during or after the death of theinfected cells.The observation smade in this study have comfimed in the granular cell of the cerebellum theidea of Chert et al.that the encephalitis B virus particle can he formed in the perinudear cistem ofthe infected nerve cell,and have brought forth further information in this respect.The way of releaseof the virus particles from the infected nerve cells observed in this study is fundamentally consistentwith that observed by Chen et al.but most of the virus particles left the nerve cell via the cell pro-

Ultrastructural Pathology of Nerve Cells in Mouse Brain Infected with Epidemic B Encephalitis Virus

An animal model of epidemic(Japanese)B encephalitis was estabilisged by injecting the Jin Wei Yah 1 stain of B encephalitis virus into the peritoneal cavity of mice.The ultrastructural changes of the nerve cells in their brains were studied,special attention being paid to some types of nerve cell in the cerebellar cortex.The infectet Purkinje cells and especially the granular cells showed special and inter,sting pathological features.These were compared with the changes found in the in- fected nerve cells in the cerebral cortex,diencephalon and mesencephalon. A radiating structure consisting of a microveside-microtubule aggregation body at the center and endoplastic reticulum or virus replication multivesicular structures around it was often found in the in fected nerve cells.Its morphological features were described in detail,and its significance and the se- quenoe of events of its development discussed. In the late stage of infection,virus particles were found in the nuclei of part of the necrotic cells.It is considered that they entered the nuclei from the cytoplasm during or after the death of the infected cells. The observation smade in this study have comfimed in the granular cell of the cerebellum the idea of Chert et al.that the encephalitis B virus particle can he formed in the perinudear cistem of the infected nerve cell,and have brought forth further information in this respect.The way of release of the virus particles from the infected nerve cells observed in this study is fundamentally consistent with that observed by Chen et al.but most of the virus particles left the nerve cell via the cell pro-