Linked Life Data

1698944

Source:http://linkedlifedata.com/resource/pubmed/id/1698944

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1990-11-2
pubmed:abstractText
While recent studies have established the presence of voltage-gated ion channels on Schwann cells in culture and on freshly isolated fibers from mature mammals, an important issue not yet explored is whether Schwann cell channels are regionally specialized. In the nodal region, the intimate association between the Schwann cell and its axon suggests that this is a likely site for functional specialization. Here, we examine whether there is a localized expression of channels in the Schwann cell paranodal regions, in a manner similar to that already shown for the nodal axon. Cell-attached and outside-out patch-clamp recordings were made from paranodal regions of rat myelinated sciatic nerve fibers where the myelin on both sides of the node was retracted by enzymatic treatment. Even though no myelin was visible on the surface of the retracted paranode, significant portions of this surface were found to stain positively with a marker (anti-galactocerebroside) for Schwann cell membranes, suggesting that part of the axon still was covered by glial membranes. Using Lucifer yellow in the recording pipettes, we observed that the dye diffused into either axons or Schwann cells when the membrane under the tip was ruptured. Using this as a criterion to identify membranes obtained from retracted paranodes, we found delayed and inwardly rectifying potassium channels on both axon- and Schwann-derived patches. However, sodium channels were detected only in axon patches. This is the first report that voltage-gated glial channels are present in immediate vicinity to axons of the PNS. This finding, coupled with earlier reports that functional channels are absent in soma of mature myelinating Schwann cells, suggests that ion channels in these cells are regionally specialized for functional interaction with axons.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
10
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3263-74
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Ion channels in axon and Schwann cell membranes at paranodes of mammalian myelinated fibers studied with patch clamp.
pubmed:affiliation
Department of Neurophysiology, University of Wisconsin, Madison 53706.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't