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rdf:type |
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lifeskim:mentions |
umls-concept:C0006675,
umls-concept:C0030685,
umls-concept:C0031760,
umls-concept:C0242842,
umls-concept:C0259942,
umls-concept:C0391871,
umls-concept:C0439831,
umls-concept:C0680255,
umls-concept:C1283071,
umls-concept:C1704448,
umls-concept:C1948027,
umls-concept:C1963578
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pubmed:issue |
5
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pubmed:dateCreated |
1997-3-26
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pubmed:abstractText |
Microphotolysis and confocal microscopy were used to investigate the timing of calcium release and of the electrical response in Limulus polyphemus ventral photoreceptors. The fluorescent dyes Fluo-3 and Calcium Green-5N were used to monitor local Ca2+ elevations. Photolysis of caged inositol trisphosphate (InsP3) close to the plasma membrane of the light-sensitive rhabdomeral (R-) lobe resulted in Ca2+ elevation within 10-20 msec, 20-45 msec before the physiological response to light normally would be detected. Inward ionic current flow and depolarization followed InsP3-induced calcium release within 2.5 +/- 3.3 msec. Voltage-clamping the cells and removal of extracellular Ca2+ did not affect the timing of the Ca2+ elevation that followed the photolysis of caged InsP3 or its relationship to the electrical response. In contrast to the physiological response to light, which only released calcium within the R-lobe, photolysis of InsP3 elevated Cai in both lobes, although with much greater effect in the R-lobe, as compared with the bulk of the A-lobe, suggesting the presence of InsP3-sensitive calcium stores in both lobes. Photolysis of caged calcium [o-nitrophenyl EGTA (NPE)] at the edge of the R-lobe activated an inward ionic current within 1.8 +/- 0.7 msec. This NPE-induced current reversed at a membrane potential of 10 +/- 6 mV in the range typical of that of the light-activated current under physiological conditions. Calcium release, therefore, activates an inward current rapidly enough to contribute to the electrical response to light.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/2-nitrophenyl-EGTA,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Aniline Compounds,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Egtazic Acid,
http://linkedlifedata.com/resource/pubmed/chemical/Fluo-3,
http://linkedlifedata.com/resource/pubmed/chemical/Fluorescent Dyes,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine Diphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Inositol 1,4,5-Trisphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Organic Chemicals,
http://linkedlifedata.com/resource/pubmed/chemical/P(3)-1-(2-nitro)phenylethyladenosine...,
http://linkedlifedata.com/resource/pubmed/chemical/Thionucleotides,
http://linkedlifedata.com/resource/pubmed/chemical/Xanthenes,
http://linkedlifedata.com/resource/pubmed/chemical/calcium green,
http://linkedlifedata.com/resource/pubmed/chemical/guanosine 5'-O-(2-thiodiphosphate),
http://linkedlifedata.com/resource/pubmed/chemical/inositol 1,4,5-trisphosphate...
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pubmed:status |
MEDLINE
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pubmed:month |
Mar
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pubmed:issn |
0270-6474
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
17
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1701-9
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:9030629-Action Potentials,
pubmed-meshheading:9030629-Adenosine Triphosphate,
pubmed-meshheading:9030629-Aniline Compounds,
pubmed-meshheading:9030629-Animals,
pubmed-meshheading:9030629-Calcium,
pubmed-meshheading:9030629-Drosophila melanogaster,
pubmed-meshheading:9030629-Egtazic Acid,
pubmed-meshheading:9030629-Fluorescent Dyes,
pubmed-meshheading:9030629-Guanosine Diphosphate,
pubmed-meshheading:9030629-Horseshoe Crabs,
pubmed-meshheading:9030629-Inositol 1,4,5-Trisphosphate,
pubmed-meshheading:9030629-Microchemistry,
pubmed-meshheading:9030629-Microscopy, Confocal,
pubmed-meshheading:9030629-Optic Nerve,
pubmed-meshheading:9030629-Organic Chemicals,
pubmed-meshheading:9030629-Patch-Clamp Techniques,
pubmed-meshheading:9030629-Photolysis,
pubmed-meshheading:9030629-Photoreceptor Cells, Invertebrate,
pubmed-meshheading:9030629-Second Messenger Systems,
pubmed-meshheading:9030629-Species Specificity,
pubmed-meshheading:9030629-Thionucleotides,
pubmed-meshheading:9030629-Xanthenes
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pubmed:year |
1997
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pubmed:articleTitle |
Rapid coupling of calcium release to depolarization in Limulus polyphemus ventral photoreceptors as revealed by microphotolysis and confocal microscopy.
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pubmed:affiliation |
Department of Zoology, University of Maryland, College Park, Maryland 20742, USA.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, U.S. Gov't, P.H.S.
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