Bral1: Its Role in Diffusion Barrier Formation and Conduction Velocity in the CNS

• DOI: 10.1523/jneurosci.5598-09.2010
• Publication Date: 2010-02-24T18:28:22Z
• Authors: Yoko Bekku; Lýdia Vargová; Yoshinobu Goto; Ivan Vorísek; Lesia Dmytrenko; Masahiro Narasaki; Aiji Ohtsuka; Reinhard Fässler; Yoshifumi Ninomiya; Eva Syková; Toshitaka Oohashi
• Keywords: Versican; Node of Ranvier

At the nodes of Ranvier, excitable axon membranes are exposed directly to extracellular fluid. Cations accumulated and depleted in local nodal region during action potential propagation, but impact extranodal micromilieu on signal propagation still remains unclear. Brain-specific hyaluronan-binding link protein, Bral1, colocalizes forms complexes with negatively charged matrix (ECM) proteins, such as versican V2 brevican, at Ranvier myelinated white matter. The protein family, including appears be linchpin these hyaluronan-bound ECM complexes. Here we report that hyaluronan-associated no longer shows a pattern CNS nerve conduction is markedly decreased Bral1-deficient mice even though there were differences between wild-type mutant clustering or transition ion channels tissue morphology around Ranvier. However, changes space diffusion parameters, measured by real-time iontophoretic method diffusion-weighted magnetic resonance imaging (MRI), suggest reduction hindrances matter mice. These findings provide better understanding mechanisms underlying accumulation cations due barriers saltatory conduction, which further implies importance Bral1-based extramilieu for neuronal conductivity.