Gap Junction Contributions to the Goldfish Electroretinogram at the Photopic Illumination Level.
10.4196/kjpp.2012.16.3.219
- Author:
Doh Yeon KIM
1
;
Chang Sub JUNG
Author Information
1. Natural Sciences Section, Department of Medical Lifescience, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea. cjung@catholic.ac.kr
- Publication Type:Original Article
- Keywords:
Electroretinogram;
b-wave;
Gap-junction;
Nitric oxide;
Dopamine
- MeSH:
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine;
Benzazepines;
Dopamine;
Electrodes;
Eye;
Gap Junctions;
Goldfish;
Humans;
Intravitreal Injections;
Light;
Lighting;
Meclofenamic Acid;
Neurons;
Neurosciences;
NG-Nitroarginine Methyl Ester;
Nitric Oxide;
Nitric Oxide Synthase;
Nitroprusside;
Quinpirole;
Retinal Neurons;
Sulpiride;
Tissue Donors
- From:The Korean Journal of Physiology and Pharmacology
2012;16(3):219-224
- CountryRepublic of Korea
- Language:English
-
Abstract:
Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following NG-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.
