Document Detail

Neural retinal contribution to the slow negative potential of the canine electroretinogram.
MedLine Citation:
PMID:  9858090     Owner:  NLM     Status:  MEDLINE    
To establish the normal waveform of the electrical responses from canine eyes, electroretinograms and the light peak were recorded in hybrid and beagle dogs under general anesthesia and artificial ventilation. The neural retinal and retinal pigment epithelial components were pharmacologically isolated by intravitreal glutamate injection and systemic sodium iodate administration, respectively. The a- and b-waves elicited by either flash or rectangular stimuli, the oscillatory potentials elicited by flash stimuli and the light peak elicited either by a single maintained illumination or by repetitive stimuli were almost identical with those of other vertebrates thus far studied. In contrast, in response to rectangular (several-second duration) stimuli, the c-wave was usually absent and was replaced by a slow cornea-negative potential that had a time course similar to that of the c-wave in other species. This slow negative potential was elicited at such low stimulus intensities that the a-wave was absent, was deepened by an intravenous administration of sodium iodate, was not affected by an intravitreal injection of sodium glutamate and was shallowed during the light peak. These results suggest that the slow negative potential that replaces the c-wave consists of large slow PIII, small retinal pigment epithelial c-wave and negligible contribution from the late photoreceptor potential and the dc component of the PII.
Y Shirao; R Wajima; T Kaneko; A Nishimura
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Documenta ophthalmologica. Advances in ophthalmology     Volume:  94     ISSN:  0012-4486     ISO Abbreviation:  Doc Ophthalmol     Publication Date:    1997-1998
Date Detail:
Created Date:  1999-02-04     Completed Date:  1999-02-04     Revised Date:  2006-07-19    
Medline Journal Info:
Nlm Unique ID:  0370667     Medline TA:  Doc Ophthalmol     Country:  NETHERLANDS    
Other Details:
Languages:  eng     Pagination:  293-306     Citation Subset:  IM    
Department of Ophthalmology, Kanazawa University School of Medicine, Ishikawa, Japan.
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MeSH Terms
Action Potentials / physiology
Dogs / physiology*
Electroretinography / drug effects
Iodates / pharmacology
Neuroglia / physiology*
Photic Stimulation
Pigment Epithelium of Eye / drug effects
Retina / drug effects,  physiology*
Sodium Glutamate / pharmacology
Synaptic Transmission / drug effects
Reg. No./Substance:
0/Iodates; 142-47-2/Sodium Glutamate; 7681-55-2/sodium iodate

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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