Quantitative study of the infection in brain neurons in human rabies

Rabies virus is a highly neuronotropic virus that causes encephalomyelitis. Rabies virus infection was studied in neurons in the brain of an 8-year-ol d girl that died of rabies in Mexico.The extent of the neuronal infection w as evaluated quantitatively in neuronal cell types of the brain using histo logic staining for Negri bodies and immunoperoxidase staining for rabies vi rus antigen in the same neurons. Quantitative image analysis was used to co mpare the amount of infection in five different neuronal cell types, which was expressed as a percentage of neuronal area. Purkinje cells and periaque ductal gray neurons showed the largest percentage area for both Negri bodie s and signal for rabies virus antigen. In general, there was a good linear relationship between the area of Negri bodies and the area of signal for ra bies virus antigen. Many neurons with rabies virus antigen did not have Neg ri bodies, however, and some neurons with large antigen signals, especially Purkinje cells and periaqueductal gray neurons, lacked Negri bodies. Forma tion of Negri bodies is likely influenced by factors that vary in different neuronal cell types. (C) 2001 Wiley-Liss, Inc.