Localization of catecholamines in the buccal ganglia of Aplysia californica.

The distribution of catecholamines and serotonin in the buccal ganglia and buccal nerves of Aplysia californica was examined using glyoxylic acid-induced histofluorescence. Three identifiable, medium-sized cell bodies, two paired and one unpaired, and 5 smaller cells fluoresced blue-green indicating the presence of catecholamines. Numerous fluorescent axons were observed in the neuropil and peripheral nerves, including a network of catecholaminergic processes emerging from the esophageal nerve and surrounding the base of the esophagus. The presence of catecholaminergic cells and processes in the buccal system suggests that these transmitters are used in the control of feeding behavior and digestion.