Metabotropic glutamate receptor-mediated hetero-synaptic interaction of red- and green-cone inputs to LHC of carp retina.
The role of presynaptic metabotropic glutamate receptor (mGluR) on the interaction of red- and green-cone signals was investigated in luminosity-type horizontal cell (LHC) of isolated carp retina. It was found that a dim red background could enhance LHC's light response to green stimulus, and a dim green background was also able to increase the cell's response to red flash. Such mutual color enhancement was eliminated by application of groups II and III mGluR antagonist (S)-methyl-4-carboxyphenyl-glycine (MCPG). Furthermore, inhibition of glutamate uptake by using D-aspartate (D-Asp) or DL-threo-beta-hydroxy-aspartic acid (THA) completely blocked the mutual enhancement of color signals in LHC. However, the GABAergic feedback pathway in the outer retina was unnecessarily involved.
Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, PR China.
Fu-Jun
FJ
Luo
Pei-Ji
PJ
Liang
D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D002347:Carps; D003116:Color; D026603:D-Aspartic Acid / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives* / Q000494:pharmacology; D066298:In Vitro Techniques; D007395:Interneurons / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D010775:Photic Stimulation; D010852:Picrotoxin / Q000494:pharmacology; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D012160:Retina / Q000166:cytology* / Q000187:drug effects; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D001224:Aspartic Acid; D026603:D-Aspartic Acid; D018756:GABA Antagonists; D005998:Glycine; D010852:Picrotoxin; D018094:Receptors, Metabotropic Glutamate; D005680:gamma-Aminobutyric Acid; C453101:carboxyphenylglycine; C011274:3-hydroxyaspartic acid