Linked Life Data

9157313

Source:http://linkedlifedata.com/resource/pubmed/id/9157313

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-5-22
pubmed:abstractText
The effect of histamine on N-methyl-D-aspartate currents was investigated in pyramidal neurons in the CA1 region of acute hippocampal slices from juvenile rats. The objective was to compare histamine effects in the slice with those previously reported in acutely dissociated and cultured hippocampal neurons. Micromolar concentrations of histamine had no effect on N-methyl-D-aspartate mediated excitatory postsynaptic currents in the slice, in contrast to the large enhancement seen in culture under identical conditions. However, millimolar concentrations of histamine blocked these currents both in the slice and in culture. Possible reasons for the lack of enhancement in the slice were explored as follows. (1) Histamine could not penetrate the slice or was already present at high concentrations inside the slice. This was tested by recording N-methyl-D-aspartate currents elicited in outside-out patches pulled from the somas of CA1 slice neurons. Histamine still had no effect in patches, whereas the corresponding experiment for cultured neurons showed robust enhancement. (2) Slices release an endogenous ligand that binds with high affinity to the histamine site on the N-methyl-D-aspartate receptor, blocking its activation. This was tested by superfusing cultures with supernatant from homogenized slice tissue. Histamine enhancement was maintained in these cultures. (3) CA1 slices and cultures express different N-methyl-D-aspartate receptor subtypes. The reverse transcription-polymerase chain reaction technique was used to examine the expression of messenger RNA encoding N-methyl-D-aspartate receptor subunits in the two systems. No difference was found in the whole-tissue expression of messenger RNA for the NR2A, 2B or 2C subunits or for the eight known splice variants of the NR1 subunit. It is hypothesized that the differential enhancing effect of histamine in slices and culture involves posttranslational modifications or other factors that modulate the N-methyl-D-aspartate receptor/ion channel according to its environment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
669-77
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Differential effects of histamine on the N-methyl-D-aspartate channel in hippocampal slices and cultures.
pubmed:affiliation
Divisions of Neuroscience and Biochemistry, John Curtin School of Medical Research, Australian National University, Canberra, Australia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't