Kv3.1b is a novel component of CNS nodes.

Published

Journal Article

We herein demonstrate that Kv3.1b subunits are present at nodes of Ranvier in the CNS of both rats and mice. Kv3.1b colocalizes with voltage-gated Na+ channels in a subset of nodes in the spinal cord, particularly those of large myelinated axons. Kv3.1b is abundantly expressed in the gray matter of the spinal cord, but does not colocalize with Na+ channels in initial segments. In the PNS, few nodes are Kv3.1b-positive. During the development of the CNS, Kv3.1b clustering at nodes occurs later than that of Na+ channels, but precedes the juxtaparanodal clustering of Kv1.2. Moreover, in myelin-deficient rats, which have severe CNS dysmyelination, node-like clusters of Kv3.1b and Na+ channels are observed even in regions devoid of oligodendrocytes. Ankyrin G coimmunoprecipitates Kv3.1b in vivo, indicating that these two proteins may interact in the CNS at nodes. 4-Aminopyridine, a K+ channel blocker, broadened the compound action potential recorded from adult rat optic nerve and spinal cord, but not from the sciatic nerve. These effects were also observed in Kv3.1-deficient mice. In conclusion, Kv3.1b is the first K+ channel subunit to be identified in CNS nodes; but Kv3.1b does not account for the effects of 4-aminopyridine on central myelinated tracts.

Full Text

Duke Authors

Cited Authors

  • Devaux, J; Alcaraz, G; Grinspan, J; Bennett, V; Joho, R; Crest, M; Scherer, SS

Published Date

  • June 2003

Published In

Volume / Issue

  • 23 / 11

Start / End Page

  • 4509 - 4518

PubMed ID

  • 12805291

Pubmed Central ID

  • 12805291

Electronic International Standard Serial Number (EISSN)

  • 1529-2401

International Standard Serial Number (ISSN)

  • 0270-6474

Digital Object Identifier (DOI)

  • 10.1523/jneurosci.23-11-04509.2003

Language

  • eng