Linked Life Data

2460620

Source:http://linkedlifedata.com/resource/pubmed/id/2460620

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-12-5
pubmed:abstractText
Astrocytes (both type 1 and type 2), cultured from the central nervous system of newborn or 7 day old rats show voltage gated sodium and potassium channels that are activated when the membrane is depolarized to greater than -40 mV. The sodium channels in these cells have an h-infinity curve similar to that of nodal membranes but the activation (peak current-voltage) curves are shifted along the voltage axis by about +30 mV. These sodium currents are blocked only by high concentrations of tetrodotoxin. The voltage activated potassium currents in both types of astrocyte show at least two components; an inactivating component that is suppressed at holding potentials of greater than -40 mV and a persistent, non-inactivating current. Several types of single channel currents were observed in outside-out membrane patches from type 2 astrocytes. One type of potassium channel showed inactivation on depolarization and may contribute to the whole-cell inactivating current. In contrast, oligodendrocytes showed no obvious voltage gated membrane channels. The properties of the type 2 astrocyte-oligodendrocyte progenitor cell were investigated in two ways: 1) by examination of cells just beginning to differentiate along the "electrically silent" oligodendrocyte pathway or 2) by recording from progenitor cells cultured for 24 hours in the presence of cycloheximide to block the appearance of new membrane channels. In both cases, voltage gated inward (sodium) and outward (potassium) currents were noted. The outward current response showed both an inactivating and a non-inactivating component. Similar voltage activated inward and outward membrane currents were noted in reactive astrocytes freshly isolated (3-6 hours) from lesioned areas of adult rat brains.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0021-7948
pubmed:author
pubmed:issnType
Print
pubmed:volume
82
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
327-35
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Voltage gated ionic channels in rat cultured astrocytes, reactive astrocytes and an astrocyte-oligodendrocyte progenitor cell.
pubmed:affiliation
Department of Zoology, University College London, U.K.
pubmed:publicationType
Journal Article