An Attempt to Identify Putative Neurotransmitter Molecules in the Central Nervous System of the Snail

Abstract

Two classes of substances, amines and amino acids, were investigated as potential neurotransmitters in the central nervous system of the snail Helix pomatia. The authors were able to demonstrate the presence of physiologically important amines and amino acids such as 5-HT, tyramine, tryptamine, adrenaline, noradrenaline, dopamine, and Dopa in all parts of the brain. GABA was found to be present mostly in its γ-lactame form and its identity was verified by using mass spectrometry. The presence of polyamines such as putrescine, spermine and spermidine was also established by means of mass spectrometry. Several indol-derivates such as tryptophan, 5-HTP, 6-HTP and 5-HT, 6-HT and 5,6-HT were found to be present. Amines and amino acids differed both qualitatively and quantitatively among the different parts of the snail brain, however, no differences in composition were discovered between left and right ganglia.