Claudin 11 stops the leaks in neuronal myelin sheaths
December 1, 2008Devaux and Gow demonstrate how a tight junction protein called claudin 11 makes the neuronal myelin sheath a snug fit. The study will be published in the December 1, 2008 issue of the Journal of Cell Biology.
Like the rubber coating on a copper wire, the myelin sheath—a membrane extension of glial cells that spirals around the axons of neurons—creates an insulation layer that prevents current leakage from axons and aids electrical conduction along the length of the axon.
Claudin 11 forms tight junctions between successive spiral layers of the myelin sheath, but it was unknown whether it was required for myelin to act as a good insulator. To examine this question, Devaux and Gow compared electrical recordings from the optic nerve of wild-type and claudin 11 knockout mice. They found that although claudin 11 deficiency caused no gross defects in the appearance of the myelin sheath, it slowed electrical signals—at least in neurons with small-diameter axons.
Using a computer model that incorporates the resistive and capacitive properties of axons (and their myelin sheaths), the authors showed that claudin 11 adds to the electrical resistance of myelin by preventing leakage of charged ions (and electrical current) through the spiral space between myelin layers. The reduced resistance in the absence of claudin 11 affects small-diameter axons most severely because such axons have thinner myelin sheaths and thus less insulation to begin with. Because neurons with small-diameter axons are mostly found in the CNS, the authors speculate that defects in claudin 11 could be associated with deficits in cognition and perception, like those found in schizophrenia or neurodegenerative diseases.
Citation: Devaux, J., and A. Gow. 2008. J. Cell Biol. doi:10.1083/jcb.200808034. (www.jcb.org" targe … >www.jcb.org)
Source: Rockefeller University
-
Engineers build first sub-10-nm carbon nanotube transistor
Feb 01, 2012 |
4.9 / 5 (33) |
30
-
Something old, something new: Evolution and the structural divergence of duplicate genes
Jan 31, 2012 |
4.6 / 5 (7) |
1
-
The hidden nanoworld of ice crystals: Revealing the dynamic behavior of quasi-liquid layers
Jan 30, 2012 |
5 / 5 (4) |
1
-
Stock market network reveals investor clustering
Jan 27, 2012 |
3.9 / 5 (23) |
8
-
Of microchemistry and molecules: Electronic microfluidic device synthesizes biocompatible probes
Jan 26, 2012 |
5 / 5 (2) |
0
More news stories
Integrated pest management recommendations for the southern pine beetle
The southern pine beetle, Dendroctonus frontalis Zimmermann, is a chronic insect pest within pine forests in the southeastern United States. Under favorable environmental and host conditions, it is an agg ...
40 minutes ago |
not rated yet |
0
A mitosis mystery solved: How chromosomes align perfectly in a dividing cell
Although the process of mitotic cell division has been studied intensely for more than 50 years, Whitehead Institute researchers have only now solved the mystery of how cells correctly align their chromosomes during symmetric ...
15 hours ago |
4.5 / 5 (22) |
0
|
Researchers find extensive RNA editing in human transcriptome
In a new study published online in Nature Biotechnology, researchers from BGI, the world's largest genomics organization, reported the evidence of extensive RNA editing in a human cell line by analysis of RNA-seq data, demons ...
15 hours ago |
5 / 5 (4) |
0
|
The proteins ensuring genome protection
Researchers from the University of Geneva (UNIGE), Switzerland, have discovered the crucial role of two proteins in developing a cell 'anti-enzyme shield'. This protection system, which operates at the level of molecular ...
15 hours ago |
5 / 5 (3) |
0
|
Entire genome of extinct human decoded from fossil
(PhysOrg.com) -- In 2010, Svante Pääbo and his colleagues presented a draft version of the genome from a small fragment of a human finger bone discovered in Denisova Cave in southern Siberia. The ...
Feb 07, 2012 |
4.7 / 5 (60) |
51
|
Japan's Fukushima reactor may be reheating: operator
Temperature readings at one of the crippled Fukushima nuclear reactors have risen above Japan's stringent new safety standard but there was no immediate danger, its operator said Sunday.
Botox developer rues missing out on billions
Botox developer Alan Scott says he rues the day he handed over rights to the best-selling wrinkle-smoothing drug to a US company for just $4.5 million, saying he might have become a billionaire.
Cognitive impairment in older adults often unrecognized in the primary care setting
A new study published in the Journal of the American Geriatrics Society reveals that brief cognitive screenings combined with offering further evaluation increased new diagnoses of cognitive impairment in older veterans two to ...
AT&T customers surprised by 'unlimited data' limit
(AP) -- Mike Trang likes to use his iPhone 4 as a GPS device, helping him get around in his job. Now and then, his younger cousins get ahold of it, and play some YouTube videos and games.
Australian women reject 'I love u' texts
Australian women may have embraced the digital era, but they prefer a face-to-face declaration of affection to an "I love u" text and find men addicted to their mobile phones a major turnoff.
Many lung cancer patients get radiation therapy that may not prolong their lives
A new study has found that many older lung cancer patients get treatments that may not help them live longer. Published early online in CANCER, a peer-reviewed journal of the American Cancer Society, the findings suggest that p ...