Document Detail


The oscillatory potentials of the mudpuppy retina.
MedLine Citation:
PMID:  721390     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The properties of the oscillatory potentials (OPs) of the mudpuppy electroretinogram (ERG) were studied and compared with the properties of the b-wave of the ERG and the proximal negative response (PNR). Both transretinal and intraretinal ERGs were recorded in response to full-field as well as 200 and 500 microgram spot illumination. The OPs differed in behavior from the b-wave in terms of voltage-response relations and the effects of repetitive stimuli. Thus the OPs appear to have a different origin from that of the b-wave. The laminar profile of the OPs was also compared with both the PNR and the b-wave. The OPs reverse in polarity as a function of retinal depth and therefore appear to reflect radial flows of currents within the retina. Thus the origin of the OPs seems different also from that of the PNR, which appears to represent tangential current flows around the amacrine cells. The earlier OPs arise more proximally within the retina than the later ones, suggesting that the individual oscillatory peaks are likely to have different origins. We propose that the OPs may represent feedback loops within retina. In support of this notion, it was found that the OPs were selectively depressed by GABA, glycine, glutamate, and dopamine. Acetylcholine and carbacholine did not affect the oscillatory responses, suggesting perhaps that the OPs are generated by inhibitory feedback synaptic circuits.
Authors:
L Wachtmeister; J E Dowling
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Investigative ophthalmology & visual science     Volume:  17     ISSN:  0146-0404     ISO Abbreviation:  Invest. Ophthalmol. Vis. Sci.     Publication Date:  1978 Dec 
Date Detail:
Created Date:  1979-02-21     Completed Date:  1979-02-21     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7703701     Medline TA:  Invest Ophthalmol Vis Sci     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1176-88     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Action Potentials / drug effects
Animals
Dopamine / pharmacology
Electrophysiology / instrumentation,  methods
Electroretinography
Glutamates / pharmacology
Glycine / pharmacology
Retina / physiology*
Urodela
gamma-Aminobutyric Acid / pharmacology
Chemical
Reg. No./Substance:
0/Glutamates; 56-12-2/gamma-Aminobutyric Acid; 56-40-6/Glycine

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


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