Contribution of proximal retinal neurons to b- and d-waves of frog electroretinogram under different conditions of light adaptation.
The effects of pharmacological blockade of the proximal retinal activity by N-methyl-D-aspartate (NMDA) on the V-log I function of the ERG b- and d-waves were studied in dark and light adapted frog eyes. The effects of NMDA depended on the type of photoreceptor input. In rod-dominated ERG the b-wave amplitude was decreased by NMDA, but that of the d-wave remained unchanged. In cone-dominated ERG the b-wave amplitude was increased while the d-wave amplitude was decreased. Thus, the b/d amplitude ratio was decreased in rod-dominated, but increased in cone-dominated ERG. Our results imply that the b/d amplitude ratio would be changed in an opposite way in the rod- and cone-dominated ERG, when the function of the proximal retinal neurons is compromised.
Popova
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Department of Physiology, Medical Faculty, Medical University, 1431 Sofia, Bulgaria. epopova@abv.bg
Kupenova
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D000221:Adaptation, Ocular / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D003623:Dark Adaptation / Q000502:physiology; D004596:Electroretinography; D016202:N-Methylaspartate; D010775:Photic Stimulation / Q000379:methods; D011895:Rana ridibunda; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D055351:Retinal Neurons / Q000187:drug effects / Q000502:physiology*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology
D016202:N-Methylaspartate