Rabies (and rabies virus, its causative agent) is usually transmitted through the bite of an infected animal into muscle tissue of the new host. From there, the virus travels all the way to the brain, where it multiplies and causes the usually fatal disease. An article published online on August 28, 2014 in the open-access journal PLOS Pathogens sheds light on how the virus hijacks the transport system in nerve cells to reach the brain with maximal speed and efficiency. Pathogens that travel in the blood can spread throughout the body without much effort, courtesy of the heart's pumping action. Those traveling outside the blood stream and needing to cover large distances—like rabies virus which depends on the nerve cell network—need to utilize other means of transport. Nerve cells (or neurons) in the periphery, i.e., at the outskirts of the body, as opposed to the central nervous system or CNS), are highly asymmetric: they have a cell body from which a long protrusion called an axon extends to another nerve cell or a target organ like muscle, along a specific transmission route. Axons can measure several hundred times the diameter of the cell body, and, in addition to rapid transmission of electric impulses, they also transport molecular materials over these distances. Rabies virus is known to somehow use this transport system, and Dr. Eran Perlson, from Tel Aviv University, Israel, and colleagues set out to examine the details of how this occurs. The researchers set up a system to grow asymmetric nerve cells in an observation chamber and use live cell imaging to track how rabies virus particles are transported along the axons. The team focused on the p75NTR receptor, a protein which is found on the tips of peripheral neurons and is known to bind a small molecule called NGF (for nerve growth factor).Login Or Register To Read Full Story