Desensitization of the GABAA receptor shifts the dynamic range of retinal horizontal cells due to light and dark adaptation.
The effects of the GABAergic pathway on the dynamic range of the light response of cone-driven horizontal cells (HCs) in the carp retina were investigated using conventional intracellular recordings and computer simulations. The amplitude of the HC responses to repetitive test flashes was altered by background illumination in control Ringer's solution, but was not changed following the application of picrotoxin or bicuculline, which suggests that GABAA receptors mediate the subsequent change in light response. This phenomenon was simulated by introducing the desensitization mechanism of the GABAA receptor into a cone-HC network model. These results suggest that desensitization of the GABAA receptor shifts the dynamic range of the HCs due to light and dark adaptation.
Kawai
F
F
Department of Information and Computer Sciences, Toyohashi University of Technology, Japan.
Kamiyama
Y
Y
Usui
S
S
D000221:Adaptation, Ocular / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D002347:Carps; D018118:Chloride Channels / Q000502:physiology; D003198:Computer Simulation; D004298:Dopamine / Q000494:pharmacology; D004594:Electrophysiology; D018756:GABA Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D015640:Ion Channel Gating; D008564:Membrane Potentials; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D010852:Picrotoxin / Q000494:pharmacology; D011963:Receptors, GABA-A / Q000502:physiology*; D012160:Retina / Q000166:cytology / Q000502:physiology*; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology
D001640:Bicuculline; D018118:Chloride Channels; D004298:Dopamine; D018756:GABA Antagonists; D010852:Picrotoxin; D011963:Receptors, GABA-A