Under the ECM Dome: The Physiological Role of the Perinodal Extracellular Matrix as an Ion Diffusion Barrier

Yoko Bekku, Toshitaka Oohashi

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

Enriched Na+ channel clustering allows for rapid saltatory conduction at a specialized structure in myelinated axons, the node of Ranvier, where cations are exchanged across the axon membrane. In the extracellular matrix (ECM), highly negatively charged molecules accumulate and wrap around the nodal gaps creating an ECM dome, called the perinodal ECM. The perinodal ECM has different molecular compositions in the central nervous system (CNS) and peripheral nervous system (PNS). Chondroitin sulfate proteoglycans are abundant in the ECM at the CNS nodes, whereas heparan sulfate proteoglycans are abundant at the PNS nodes. The proteoglycans have glycosaminoglycan chains on their core proteins, which makes them electrostatically negative. They associate with other ECM molecules and form a huge stable ECM complex at the nodal gaps. The polyanionic molecular complexes have high affinity to cations and potentially contribute to preventing cation diffusion at the nodes. In this chapter, we describe the molecular composition of the perinodal ECM in the CNS and PNS, and discuss their physiological role at the node of Ranvier.

Original languageEnglish
Title of host publicationAdvances in Experimental Medicine and Biology
PublisherSpringer
Pages107-122
Number of pages16
DOIs
Publication statusPublished - 2019
Externally publishedYes

Publication series

NameAdvances in Experimental Medicine and Biology
Volume1190
ISSN (Print)0065-2598
ISSN (Electronic)2214-8019

Keywords

  • ECM
  • Glia
  • Microenvironment
  • Node of Ranvier
  • Perinodal ECM
  • Proteoglycans

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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  • Cite this

    Bekku, Y., & Oohashi, T. (2019). Under the ECM Dome: The Physiological Role of the Perinodal Extracellular Matrix as an Ion Diffusion Barrier. In Advances in Experimental Medicine and Biology (pp. 107-122). (Advances in Experimental Medicine and Biology; Vol. 1190). Springer. https://doi.org/10.1007/978-981-32-9636-7_8