Suppression by zinc of transient OFF responses of carp amacrine cells to red light is mediated by GABA(A) receptors.
Modulation by Zn(2+) of ON and OFF responses of transient amacrine cells driven by red- and green-sensitive cones was investigated in isolated, superfused carp retina, using intracellular recording techniques. Zn(2+) selectively abolished the OFF response to red flash of the transient amacrine cells. This Zn(2+) effect was mimicked by GABA application and was blocked by bicuculline, indicating the involvement of GABA(A) receptors. Such differential modulation was observable neither in bipolar cells nor in sustained OFF amacrine cells. It is suggested that the Zn(2+) effect reported here might be due to a direct action of Zn(2+) on GABA(A) receptors of the transient amacrine cells.
Luo
Dong Gen
DG
Institute of Neurobiology, Fudan University, 220 Han-Dan Road, 200433, Shanghai, China.
Yang
Xiong Li
XL
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D025042:Amacrine Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D003118:Color Perception / Q000187:drug effects / Q000502:physiology*; D018755:GABA Agonists / Q000494:pharmacology; D018756:GABA Antagonists / Q000494:pharmacology; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; D006054:Goldfish; D008027:Light; D009433:Neural Inhibition / Q000187:drug effects / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009924:Organ Culture Techniques; D010775:Photic Stimulation; D011963:Receptors, GABA-A / Q000378:metabolism*; D018009:Receptors, Glycine / Q000037:antagonists & inhibitors / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D015032:Zinc / Q000378:metabolism* / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018755:GABA Agonists; D018756:GABA Antagonists; D058785:GABA-A Receptor Agonists; D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; D018009:Receptors, Glycine; D005680:gamma-Aminobutyric Acid; D015032:Zinc