Linked Life Data

9453664

Source:http://linkedlifedata.com/resource/pubmed/id/9453664

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-3-10
pubmed:abstractText
Conventional immunohistochemistry provides little evidence for the synaptic localization of ionotropic neurotransmitter receptors, suggesting that their epitopes are not readily accessible in situ. Here, we have adapted antigen retrieval procedures based on microwave irradiation to enhance the immunohistochemical staining of gamma-aminobutyric acid type A (GABA[A]) and N-methyl-D-aspartate (NMDA) receptor subunits in rat brain tissue. Microwave irradiation of fixed tissue produced a marked reduction of nonspecific staining, allowing an improved detection of GABA(A) receptor subunits. However, staining of NMDA receptor subunits remained suboptimal. In contrast, microwave irradiation of cryostat sections prepared from fresh tissue resulted in a major enhancement of both NMDA and GABAA receptor subunit staining. The diffuse, partially intracellular signals were largely replaced by numerous, intensely immunoreactive puncta outlining neuronal somata and dendrites, highly suggestive ofsynaptic receptors. In hippocampus CA1-CA3 fields, the NR2Aand NR2B subunit positive puncta exhibited an extensive colocalization in the stratum oriens and radiatum, whereas pyramidal cell bodies, which receive no excitatory synapses, were unstained. In addition, the NR2A subunit, but not the NR2B subunit, was selectively detected on pyramidal cell dendrites in the stratum lucidum of CA3, suggesting a selective targeting to sites of mossy fiber input. For the GABAA receptor subunits, the most striking change induced by this protocol was the selective staining of the axon initial segment of cortical and hippocampal pyramidal cells. The alpha2 subunit immunoreactivity was particularly prominent in these synapses. In control experiments, the staining of cytoskeletal proteins (neurofilaments, glial fibrillary acid protein) was not influenced by prior microwave irradiation. The enhancement of cell-surface-associated staining is therefore strongly suggestive of an 'unmasking' of subunit epitopes by the microwave treatment. These results reveal a remarkable specificity in the synaptic targeting of NMDA and GABAA receptor subunits in hippocampal and neocortical neurons, suggesting that individual neurons can express multiple receptor subtypes in functionally distinct synapses.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9967
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
390
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
194-210
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Synapse-specific localization of NMDA and GABA(A) receptor subunits revealed by antigen-retrieval immunohistochemistry.
pubmed:affiliation
Institute of Pharmacology, University of Zürich, Switzerland. fritschy@pharma.unizh.ch
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't