Determination of Amino Acids In Single Identd7iable Nerve Cells of Helix Pomatia

Abstract

Microchromatography of dansylated compounds was used to study the distribution of free amino acids, GABA, serotonin and 5-hydroxyindole in the metacerebral serotonergic cell and one of the giant cells in the buccal ganglia of Helix pomaiia. The distribution of some of the substances in each of the cell types varied depending upon the isolation procedure. Metacerebral cells dissected in the presence of nialamide contained large amounts of serotonin. The same neurons isolated in the absence of nialamide, but dissected with methylene blue contained no serotonin. The distribution of ornithine, glycine, alanine, arginine, ε-lysine, α-amino-histidine and cystine in each cell type varied depending upon the method of isolation.

Generally the distribution of dansylated substances is similar; GABA is present in each cell type but in low concentrations. However, there are some exceptions. The serotonergic cell contains less ornithine and more glycine than do the buccal cells. In addition the metacerebral cells have high amounts of an unknown substance, which may be a metabolite of serotonin.

Furthermore, 5-hydroxyindole is always found in the serotonergic cell, whilst it is present only in buccal neurons which have been dissected in the presence of nialamide.