Gamma-Aminobutyric Acid Uptake and Metabolism in 'Aplysia dactylomela',

摘要

Selected ganglia of Aplysia dactylomela were found to possess a sodium dependent gamma-aminobutyric acid (GABA) uptake system. Tissue to medium ratios as high as 20:1 were calculated in the buccal ganglion after a 45-minute incubation in 6 Micromoles GABA. The metabolism of accumulated GABA was low with 90 percent of the radioactivity remaining as GABA after a 45-minute incubation and 20-minute washout period. The buccal ganglion displayed a sodium dependent, high affinity uptake system with a Km = 52 Micromoles. No net sodium dependent accumulation was found in the pedal ganglion. In the buccal ganglion, light microscope autoradiography indicated that the sites of GABA accumulation were predominantly extraneuronal.