Herpesviruses use bidirectional fast-axonal transport to spread in sensoryneurons

Alpha herpesviruses infect the vertebrate nervous system resulting in eithe r mild recurrent lesions in mucosal epithelia or fatal encephalitis. Moveme nt of virions within the nervous system is a critical factor in the outcome of infection; however, the dynamics of individual virion transport have ne ver been assessed. Here we visualized and tracked individual viral capsids as they moved in axons away from infected neuronal cell bodies in culture, The observed movement was compatible with fast axonal flow mediated by mult iple microtubule motors. Capsids accumulated at axon terminals, suggesting that spread from infected neurons required cell contact.