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.
Luo
Fu-Jun
FJ
Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, Shanghai 200031, PR China.
Liang
Pei-Ji
PJ
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