Basis of neurovirulence in @entity12385 @entity1651 of XXXX .

@entity778 @entity4767 @entity19 @entity149 @entity281 @entity1800 @entity12385 @entity1651 @entity528 @entity912
Neuroadapted @entity12385 (NSV) was selected by serial passage of wild-type @entity12385 (SV) in @entity19 brain. After intracerebral inoculation of weanling @entity19 , NSV causes a severe @entity1651 with hindlimb @entity912 and high mortality; SV causes nonfatal mild disease. In order to determine the biologic basis of neurovirulence in vivo, these @entity1800 have been compared by using infectivity assays, light and electron microscopy, in situ hybridization, immunohistochemistry, and double-labeling for neural cell markers and viral RNA. More infectious virus is present in the central nervous system during NSV than during SV @entity281 . After intracerebral inoculation, both @entity149 and spread to gray matter areas, including the ventral horns of the spinal cord. Their cellular targets are not different, and @entity528 is prominent. NSV infects more neurons, and causes more severe injury than SV. In @entity778 , there is marked swelling of lumbar and thoracic neurons and their processes in the ventral horns. Relatively mild changes are detected in SV @entity281 only by electron microscopy. Neuroadaptation likely occurs by increasing the efficiency of viral replication in neurons, rather than by a fundamental change in the cellular tropism or the topography of the @entity4767 .
