Protecting Damaged Axons

Degeneration of axons that have been severed from their neuronal cell bodies can follow a specific course of progressive fragmentation called Wallerian degeneration. Various neurodegenerative diseases are also characterized by axonal degeneration. Araki et al. (see the Perspective by Bedalov and Simon) provide new insight into what directs the course of organized axonal degeneration. Analysis of a fusion protein resulting from a mutation that slows axon degeneration implicates the nicotinamide adenine dinucleotide biosynthetic pathway in this type of axonal degeneration. T. Araki, Y. Sasaki, J. Milbrandt, Increased nuclear NAD biosynthesis and SIRT1 activation prevent axonal degeneration. Science 305 , 1010-1013 (2004). [Abstract] [Full Text] A. Bedalov, J. A. Simon, NAD to the rescue. Science 305 , 954-955 (2004). [Summary] [Full Text]