 |
The Journal of Neuroscience, February 9, 2005, 25(6):1470-1480; doi:10.1523/JNEUROSCI.3328-04.2005
Previous Article | Next Article 
Cellular/Molecular
Altered Ion Channels in an Animal Model of Charcot-Marie-Tooth Disease Type IA
Jérôme J. Devaux and
Steven S. Scherer
Department of Neurology, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104
How demyelination and remyelination affect the function of myelinated axons is a fundamental aspect of demyelinating diseases. We examined this issue in Trembler-J mice, a genetically authentic model of a dominantly inherited demyelinating neuropathy of humans. The K+ channels Kv1.1 and Kv1.2 channels were often improperly located in the paranodal axon membrane, typically associated with improperly formed paranodes, and in unmyelinated segments between internodes. As in wild-type nerves, Trembler-J nodes contained Nav1.6, ankyrin-G, IV-spectrin, and KCNQ2, but, unlike wild-type nerves, they also contained Kv3.1b and Nav1.8. In unmyelinated segments bordered by myelin sheaths, these proteins were clustered in heminodes and did not appear to be diffusely localized in the unmyelinated segments themselves. Nodes and heminodes were contacted by Schwann cells processes that did not have the ultrastructural or molecular characteristics of mature microvilli. Despite the presence of Nav1.8, a tetrodotoxin-resistant sodium channel, sciatic nerve conduction was at least as sensitive to tetrodotoxin in Trembler-J nerves as in wild-type nerves. Thus, the profound reorganization of axonal ion channels and the aberrant expression of novel ion channels likely contribute to the altered conduction in Trembler-J nerves.
Key words: myelin; CMT; PMP22; node of Ranvier; potassium channels; axonal conduction
Received Aug 13, 2004;
revised November 22, 2004;
accepted December 16, 2004.
This article has been cited by other articles:

|
 |

|
 |
 
E. Arnaud, J. Zenker, A.-S. de Preux Charles, C. Stendel, A. Roos, J.-J. Medard, N. Tricaud, J. Weis, U. Suter, J. Senderek, et al.
SH3TC2/KIAA1985 protein is required for proper myelination and the integrity of the node of Ranvier in the peripheral nervous system
PNAS,
October 13, 2009;
106(41):
17528 - 17533.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
R. H. Baloh, A. Strickland, E. Ryu, N. Le, T. Fahrner, M. Yang, R. Nagarajan, and J. Milbrandt
Congenital Hypomyelinating Neuropathy with Lethal Conduction Failure in Mice Carrying the Egr2 I268N Mutation
J. Neurosci.,
February 25, 2009;
29(8):
2312 - 2321.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
A. Lonigro and J. J. Devaux
Disruption of neurofascin and gliomedin at nodes of Ranvier precedes demyelination in experimental allergic neuritis
Brain,
January 1, 2009;
132(1):
260 - 273.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
D. K. Mojumder, D. M. Sherry, and L. J. Frishman
Contribution of voltage-gated sodium channels to the b-wave of the mammalian flash electroretinogram
J. Physiol.,
May 15, 2008;
586(10):
2551 - 2580.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Susuki, M. N. Rasband, K. Tohyama, K. Koibuchi, S. Okamoto, K. Funakoshi, K. Hirata, H. Baba, and N. Yuki
Anti-GM1 Antibodies Cause Complement-Mediated Disruption of Sodium Channel Clusters in Peripheral Motor Nerve Fibers
J. Neurosci.,
April 11, 2007;
27(15):
3956 - 3967.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
Y. Bai, E. Ianokova, Q. Pu, K. Ghandour, R. Levinson, J.-J. Martin, C. Ceuterick-de Groote, R. Mazanec, P. Seeman, M. E. Shy, et al.
Effect of an R69C Mutation in the Myelin Protein Zero Gene on Myelination and Ion Channel Subtypes
Arch Neurol,
December 1, 2006;
63(12):
1787 - 1794.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
K. Sinha, S. Karimi-Abdolrezaee, A. A. Velumian, and M. G. Fehlings
Functional Changes in Genetically Dysmyelinated Spinal Cord Axons of Shiverer Mice: Role of Juxtaparanodal Kv1 Family K+ Channels
J Neurophysiol,
March 1, 2006;
95(3):
1683 - 1695.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|

|