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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1992-4-15
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pubmed:abstractText |
Na+ channel expression was studied in cultures of rat optic nerve astrocytes using whole-cell voltage-clamp recordings. Astrocytes from postnatal day 7 rat optic nerve (RON) expressed two distinct types of Na+ currents, which had significantly different h infinity curves. Stellate, GFAP+/A2B5+ astrocytes showed currents with h infinity curve midpoints close to -65 mV, similar to Na+ currents in most neurons. In contrast, flat fibroblast-like GFAP+/A2B5- astrocytes showed Na+ currents with h infinity midpoints around -85 mV, almost 20 mV more hyperpolarized than in neurons or A2B5+ astrocytes. Interestingly, Na+ current expression was maintained in A2B5+ astrocytes but began to decrease in A2B5- astrocytes after 6 days in vitro (DIV) and fell to or below the level of detection (i.e., 1 pA/pF) at 12 DIV. Astrocytes cultured from neonatal rats (P0) are almost exclusively GFAP+/A2B5-. These cells did not display measurable Na+ currents when studied at 2 DIV; however, Na+ current was observed after 5 DIV in A2B5- astrocytes from these neonatal (P0) cultures. These findings were substantiated by immunocytochemical experiments using 7493, an antibody raised against purified rat brain Na+ channels; in P0-derived astrocyte cultures 7493 antibody staining was initially lacking (up to 3 DIV), but it was prominent in cultures after 5 DIV, suggesting that Na+ current expression in RON astrocytes occurs postnatally.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0360-4012
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
30
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
275-87
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1665865-Animals,
pubmed-meshheading:1665865-Astrocytes,
pubmed-meshheading:1665865-Cell Aging,
pubmed-meshheading:1665865-Cells, Cultured,
pubmed-meshheading:1665865-Coloring Agents,
pubmed-meshheading:1665865-Electrophysiology,
pubmed-meshheading:1665865-Glial Fibrillary Acidic Protein,
pubmed-meshheading:1665865-Immunohistochemistry,
pubmed-meshheading:1665865-Optic Nerve,
pubmed-meshheading:1665865-Rats,
pubmed-meshheading:1665865-Rats, Inbred Strains,
pubmed-meshheading:1665865-Sodium Channels,
pubmed-meshheading:1665865-Time Factors
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pubmed:year |
1991
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pubmed:articleTitle |
Two types of Na(+)-currents in cultured rat optic nerve astrocytes: changes with time in culture and with age of culture derivation.
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pubmed:affiliation |
Department of Neurology, Yale University School of Medicine, New Haven, Connecticut 06510.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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