REAL-TIME MONITORING OF THE DOPAMINE RELEASE AND SIMULTANEOUS MEASUREMENT OF AMINO-ACIDS RELEASE IN ISOLATED CARP RETINA

The release of dopamine, amino acid neurotransmitters and other amino acids from isolated perfused carp retina was determined by using a rea l-time monitoring system. There was no detectable dopamine release dur ing exposure of the retina to darkness. Exposure to light slightly inc reased the release of dopamine. Injection of KCl into the perfusion sy stem increased the release of dopamine and of the amino acid transmitt ers glutamate (Glu), aspartate (Asp), glycine (Gly) and gamma-aminobut yrate (GABA) in a dose-dependent manner, regardless of whether the ret inas were exposed to light or darkness. The release of other amino aci ds, including taurine (Tau), arginine (Arg) and tyrosine (Tyr), was re latively unaffected by KCl treatment. The results suggest that the dir ect monitoring system is useful for studies on retinal transmitters in cluding their regulatory mechanisms and roles in visual processing.