Journal of Neuroscience, Vol 9, 3243-3249, Copyright © 1989 by Society for Neuroscience
Interganglionic axonal transport of neuropeptides in Aplysia
PE Lloyd
Department of Pharmacological and Physiological Sciences, University of Chicago, Illinois 60637.
The transport of neuropeptides between central ganglia was studied in
Aplysia. Peptide transport was determined by incubating ganglia with
35S-methionine and measuring the appearance of labeled peptides in
connected ganglia. Selected interganglionic connectives were left intact
and passed through a diffusion barrier separating the ganglia. Labeled
peptides transported between ganglia included FMRFamide, myomodulin, and
pedal peptide. Each of these peptides has been shown to be physiologically
active in Aplysia. In addition to these previously characterized
neuropeptides, a number of other as yet uncharacterized labeled peptides
were also transported. All the peptides were transported by fast axonal
transport as judged by the distance transported and/or the sensitivity to
colchicine. Overall, FMRFamide and several unidentified peptides were the
predominant transported peptides. However, the nature and amount of the
peptides transported differed for each ganglia. These results support the
proposition that the labeled peptides have transmitterlike actions and
suggest that there are a number of neuropeptides that are likely to have
central actions that have not yet been characterized in Aplysia.