Formation of Serotonin by Isolated Serotonin‐containing Neurons and by Isolated Non‐amine‐containing Neurons

Isolated giant serotonin‐containing neurons of the cerebral ganglia of Helix pomatia were shown to produce serotonin when incubated with 5‐hydroxytryptophan (5‐HTP) whereas cells of the buccal ganglia, which are non‐amine‐containing cells did not. The rate of production was comparable to that for Ach in the isolated neurons of Aplysia. The significance of these results is discussed.