Abstract
Microchromatography of dansylated substances was used to estimate the serotonin content of a giant serotonin-containing neuron situated in the metacerebral ganglia of Helix pomatia. Perfusion of the central nervous system of this snail with 14C-5-HTP showed that the giant serotonin-containing neuron can use this precursor to form 14C-serotonin, whereas a non-amine containing cell can not. The significance of these results is discussed.