Source:http://linkedlifedata.com/resource/pubmed/id/16190889
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
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| pubmed:dateCreated |
2005-9-29
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| pubmed:abstractText |
The scaffold protein family Homer/Vesl serves to couple surface receptors or channels with endoplasmic calcium release channels. Homer 1a/Vesl-1S is regarded as regulating such coupling in an activity-dependent manner. The present calcium photometry and electrophysiological measurement revealed that Homer 1a up-regulates voltage-dependent calcium channels (VDCCs), depending on inositol-1,4,5-trisphosphate (IP3) receptors (IP3Rs). In rat neocortex pyramidal cells, intracellular injection by diffusion from the patch pipette (referred to as 'infusion') of Homer 1a protein enhanced spike-induced calcium increase, depending on both the protein concentration and spike frequency. Induction of this enhancement was disrupted by blockers of key molecules of the mGluR-IP3 signalling pathway, including metabotropic glutamate receptors (mGluRs), phospholipase C and IP3Rs. However, infusion of IP3 failed to mimic the effect of Homer 1a, suggesting requirement for a second Homer 1a-mediated signalling as well as the mGluR-IP3 signalling. In contrast to the induction, maintenance of this enhancement was independent of the mGluR-IP3 signalling, taking the form of augmented calcium influx via L-type VDCCs. Presumably due to the VDCC up-regulation, threshold currents for calcium spikes were reduced. Given that Homer 1a induction is thought to down-regulate neural excitability and hence somatic spike firing, this facilitation of calcium spikes concomitant with such attenuated firing may well have a critical impact on bi-directional synaptic plasticity.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
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| pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels, L-Type,
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Homer protein,
http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Metabotropic Glutamate,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Type C Phospholipases
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| pubmed:status |
MEDLINE
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| pubmed:month |
Sep
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| pubmed:issn |
0953-816X
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| pubmed:author | |
| pubmed:issnType |
Print
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| pubmed:volume |
22
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
1338-48
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| pubmed:dateRevised |
2007-11-15
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| pubmed:meshHeading |
pubmed-meshheading:16190889-Animals,
pubmed-meshheading:16190889-Calcium,
pubmed-meshheading:16190889-Calcium Channels, L-Type,
pubmed-meshheading:16190889-Calcium Signaling,
pubmed-meshheading:16190889-Carrier Proteins,
pubmed-meshheading:16190889-Electrophysiology,
pubmed-meshheading:16190889-Electroshock,
pubmed-meshheading:16190889-Male,
pubmed-meshheading:16190889-Membrane Potentials,
pubmed-meshheading:16190889-Neocortex,
pubmed-meshheading:16190889-Patch-Clamp Techniques,
pubmed-meshheading:16190889-Photometry,
pubmed-meshheading:16190889-Pyramidal Cells,
pubmed-meshheading:16190889-Rats,
pubmed-meshheading:16190889-Rats, Wistar,
pubmed-meshheading:16190889-Receptors, Metabotropic Glutamate,
pubmed-meshheading:16190889-Recombinant Proteins,
pubmed-meshheading:16190889-Seizures,
pubmed-meshheading:16190889-Type C Phospholipases
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| pubmed:year |
2005
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| pubmed:articleTitle |
Homer 1a enhances spike-induced calcium influx via L-type calcium channels in neocortex pyramidal cells.
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| pubmed:affiliation |
Department of Integrative Brain Science, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
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| pubmed:publicationType |
Journal Article
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