Fukushima J. Med. Sci.,
Vol. 55, No. 1, 2009

[Review Article]

ROLE FOR NETRIN-1 IN SENSORY AXONAL GUIDANCE
IN HIGHER VERTEBRATES

TOMOYUKI MASUDA, CHIE SAKUMA and HIROYUKI YAGINUMA

Department of Anatomy, Fukushima Medical University School of Medicine, Fukushima 960-1295, Japan

(Received January 17, 2009, accepted March 17, 2009)

Abstract: Abstract : During development, dorsal root ganglion (DRG) neurons in higher vertebrates extend their axons centrally to the spinal cord through the dorsal root entry zone (DREZ) and peripherally to muscle and skin targets. After entering the spinal cord, DRG axons project into the dorsal mantle layer. In this review, we focus on evidence showing the role for netrin-1 in forming sensory axonal trajectories. Netrin-1 is a diffusible axonal guidance molecule that chemorepels developing DRG axons. When DRG axons project toward the DREZ, ventral spinal cord-derived netrin-1 prevents DRG axons from projecting aberrantly toward the ventral spinal cord. At later stages, the dorsal spinal cord cells transiently express netrin-1. This dorsal spinal cord-derived netrin-1 prevents DRG axons from invading the dorsal spinal cord during the waiting period. Together, the data reviewed provide strong evidence that netrin-1 plays a crucial role in sensory axon projection during development.

Key words: netrin-1, dorsal root ganglion, axon guidance, spinal cord

Dr. Tomoyuki Masuda received the 2008 Fukushima Society of Medical Science Young Researcher Award.
増田知之戮擺久間晉恵戮八木畋洋捏

Corresponding author: Tomoyuki Masuda
E-mail: tmasu@fmu.ac.jp
http://fmu.ac.jp/home/lib/F-igaku/
http://www.sasappa.co.jp/online/