ISSN:
1573-2622
Keywords:
c-wave
;
electroretinogram
;
GABA
;
light peak
;
picrotoxin
;
retinal standing potential
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Retinal potentials were recorded from the eyes of anesthetized and immobilized chicks by a standard direct current method. The amplitude of the electroretinogram (ERG) c-wave was measured 2 and 5 sec after the onset of the light stimulus, as indexes of the fast-rise c-wave (cF-wave) and the slow-rise c-wave (cs-wave), respectively. An intravitreal injection of gamma-aminobutyric acid (GABA) at an estimated intravitreal concentration of 10−9-10−7M resulted in an increase of the amplitude of the cs-wave, a less remarkable change in the a- and cF-waves, and a slight decrease in the b-wave. The light peak of the retinal standing potential increased in amplitude following GABA administration (10−7-10−4M). Following an intravitreal injection of picrotoxin (10−5-10−3M), the polarity of the cs-wave changed from positive to negative and a significant decrease and deformation in the light peak was observed. The amplitude of the a-wave, however, increased in the range of the higher dose, while that of the b- and cf-waves decreased markedly but no polarity reversal of the cF-wave was found. The results may suggest that the GABA-ergic synapse plays a significant role in production of the cs-wave and the light peak, along with that of the pigment epithelium.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00149939
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