Proteins important in Alzheimer's, Parkinson's disease travel in the slow lane

PHILADELPHIA -- Using a novel video-imaging system, researchers at the University of Pennsylvania School of Medicine have been able to observe proteins important in Alzheimer’s and Parkinson’s disease moving along axons, extensions of nerve cells that carry proteins away from the cell body. Understanding this process of axonal transport is important for studying many neurodegenerative diseases. The study appeared in the Journal of Neuroscience.
Axonal transport often breaks down and many neurodegenerative diseases are characterized by defects in this process. Of particular interest is a group of transported proteins called slow component-b that includes synuclein and tau, disease proteins involved in Parkinson’s and Alzheimer’s disease, respectively, in addition to many other proteins critical for axonal growth and regeneration.
"There are two basic transport groups called fast and slow components, with a 200 to 300 fold difference in average velocities," says first author Subhojit Roy, MD, PhD, a neuropathologist and Research Associate in the Department of Pathology and Laboratory Medicine. "While scientists have seen proteins in the fast component move rapidly to the tip of the axon, until now, mechanisms of the slow movement of these disease-related proteins have been unclear as their transport had not been directly visualized."