Amines and Amino Acids in Identified Neurons ofHelix Pomatia

A sensitive micro-procedure was used to analyze the amine and amino acid composition of identified neurons in the suboesophageal ganglia of Helix pomatia. Two of the six neurons studied were characterized by the presence of serotonin (5-hydroxytryptamine). The amino acid composition of all the neurons was similar, although in detail they differ. The predominant amino acids in the cells were ornithine, alanine, glycine, and glutamic acid. Other substances detected were tyrosine, taurine, tryptophan, lysine, phenylalanine, histidine, 5-hydroxyindole, isoleucine, leucine, valine, GABA, ethanolamine, aspartic acid, glutamine, serine, asparagine, threonine, arginine, cystine, and proline. It is concluded that because of the similar amino acid pattern in each of the six cells, information as to the functional role of individual amino acids within the neuron may best be obtained by studying their metabolism.