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 real-time monitoring system. There was no detectable dopamine release during exposure of the retina to darkness. Exposure to light slightly increased the release of dopamine. Injection of KCl into the perfusion system increased the release of dopamine and of the amino acid transmitters glutamate (Glu), aspartate (Asp), glycine (Gly) and gamma-aminobutyrate (GABA) in a dose-dependent manner, regardless of whether the retinas were exposed to light or darkness. The release of other amino acids, including taurine (Tau), arginine (Arg) and tyrosine (Tyr), was relatively unaffected by KCl treatment. The results suggest that the direct monitoring system is useful for studies on retinal transmitters including their regulatory mechanisms and roles in visual processing.