BIOGENIC MONOAMINE LEVELS IN THE CENTRAL-NERVOUS-SYSTEM OF THE SEA HARE, APLYSIA-KURODAI

1. By using a three-dimensional-coulometric HPLC system, biogenic monoamines and their metabolites were quantified simultaneously in the central nervous system of the sea hare, Aplysia kurodai. 2. Precursor amino acids, tyrosine-4 (TYR-4) and tryptophan (TRP), and dopamine (DA), 3, 4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxytryptamine (5-HT) were detected in all the ganglia examined. 3. Levels of these compounds in the cerebral, pedal and parieto-visceral ganglia were higher than those of the other ganglia examined. 4. In some ganglia, epinephrine (E), 3-O-methyldopa (30MD), 3-methoxytyramine (3-MT), dihydroxyphenylethleneglycol (DOPEG), metanephrine (MN), vanillic acid (VA), octopamine (OCT), kynurenine (KYN) and 5-hydroxyindoleacetic acid (5-HIAA) were also detected. 5. The main metabolic pathways of biogenic monoamines were shown to be TYR-4-DA-DOPAC and TRP-5-HT-5-HIAA. Furthermore, following five pathways were also suggested to be present; TYR-4-DA-E-MN-VA, TYR-4-TYRA-OCT, TYR-4-3OMD, DA-3-MT, E-DOPEG and TRP-KYN.