|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:dateCreated |
1990-12-19
|
|
pubmed:abstractText |
1. Cells in the ganglion cell layer of salamander retinal slices were voltage clamped using patch pipettes. Light elicited transient excitatory postsynaptic currents (EPSCs) in on-off ganglion cells and sustained EPSCs in on ganglion cells. Light-evoked inhibitory postsynaptic currents in these cells could be blocked by 100 microM-bicuculline methobromide and 500 nM-strychnine. 2. In the presence of external Cd2+, at a concentration that blocked light-evoked synaptic inputs, N-methyl-D-aspartate (NMDA) and the non-NMDA-receptor agonists, quisqualate and kainate, gated conductances in both on-off and on ganglion cells. The current-voltage (I-V) curve for the conductance elicited by NMDA had a negative slope between -40 and -70 mV and a reversal potential near 0 mV. The I-V curves for the non-NMDA-receptor-mediated conductances were nearly linear and also had reversal potentials near 0 mV. 3. I-V curves were measured at an early time point near the peak of transient EPSCs and at a later time point during the decay phase of the responses. The late I-V curve had a negative slope below -40 mV. The early I-V curve had a positive slope over the entire voltage range but the slope was greater at positive than at negative potentials. The evoked current reversed near 0 mV at both time points. 4. The region of negative slope of the late I-V curve was eliminated when Mg2+ was removed from the external saline. A slowly decaying component of transient EPSCs was eliminated in 20 microM-DL-2-amino-7-phosphonoheptanoate (AP7), an NMDA-receptor antagonist. 5. Application of 1 microM-6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), a non-NMDA-receptor antagonist at this concentration, blocked a fast component of transient EPSCs. 6. Our results demonstrate that the synaptic inputs to on-off ganglion cells have two components: a slower NMDA-receptor-mediated component having a time-to-peak of 110 +/- 45 ms and an e-fold decay time of 209 +/- 35 ms at -31 mV (mean +/- S.D., n = 5), and a faster non-NMDA-receptor-mediated component having a time-to-peak of 28 +/- 10 ms and an e-fold decay time of 43 +/- 20 ms at -31 mV (n = 8). 7. A similar analysis of sustained EPSCs of on ganglion cells showed that these currents resulted from sustained activation of both NMDA and non-NMDA receptors.
|
|
pubmed:grant |
|
|
pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-1128652,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-211229,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2451020,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2457089,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2549210,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2561788,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2571090,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2571688,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2580984,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2842491,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2862278,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2864779,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2865366,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2899909,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2900892,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2904492,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2908248,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-2918384,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-3019473,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-3037200,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-3199187,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-3437778,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-37522,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-438772,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-565815,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6134238,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6135763,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6141527,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6148411,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6255566,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6273752,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6320006,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6325946,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6481635,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-6825738,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-7229679,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-7229680,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-729683,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2172521-910159
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
|
|
pubmed:status |
MEDLINE
|
|
pubmed:month |
Sep
|
|
pubmed:issn |
0022-3751
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:volume |
428
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
175-97
|
|
pubmed:dateRevised |
2009-11-18
|
|
pubmed:meshHeading |
pubmed-meshheading:2172521-Ambystoma,
pubmed-meshheading:2172521-Animals,
pubmed-meshheading:2172521-Electrophysiology,
pubmed-meshheading:2172521-Glutamates,
pubmed-meshheading:2172521-Photic Stimulation,
pubmed-meshheading:2172521-Receptors, Glutamate,
pubmed-meshheading:2172521-Receptors, N-Methyl-D-Aspartate,
pubmed-meshheading:2172521-Receptors, Neurotransmitter,
pubmed-meshheading:2172521-Retinal Ganglion Cells
|
|
pubmed:year |
1990
|
|
pubmed:articleTitle |
Concomitant activation of two types of glutamate receptor mediates excitation of salamander retinal ganglion cells.
|
|
pubmed:affiliation |
Department of Ophthalmology, University of California, San Francisco 94143.
|
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, Non-U.S. Gov't
|
