Lesions of the Central Nervous System Induced by Intracerebral Inoculation of BALB/c Mice with Rabies Virus (CVS-11)

BALB/c mice were inoculated intracerebrally with fixed rabies virus (CVS-11) and pathomorphological changes in the central nervous system were studied. Infected mice showed ruffled hair, hunchback, anorexia, emaciation and ataxia at 5 days postinoculation (DPI), but paralysis did not occur. Viral antigens were first detected in the pyramidal cells of the cerebral cortex and hippocampus at 3 DPI, and these cells exhibited apoptosis at 5 DPI. Microglial cells and astroglial cells significantly increased in the areas of the nerve cells which showed apoptosis. However, spinal neurons and spinal dorsal root ganglion cells did not exhibit apoptosis despite virus infection. These observations indicate that different mechanism which causes apoptosis exists among the neurons of the brain and spinal cord, and glial cells play an important role in pathogenesis of the experimental rabies.