Interganglionic axonal transport of neural peptides within the nervous system of Aplysia.

Neurons of the circumesophageal ganglia of Aplysia synthesize 1--2000 dalton peptides and subject them to axonal transport in large quantities in the pleuro-visceral connective and pedal nerves. Most of the protein transported in the connective nerves accumulates in the abdominal ganglion, although some passes out its peripheral nerves. Autoradiography revealed no evidence for terminations of the transporting axons in possible neurohemal areas of this ganglion. It is suggested that these data reflect the existence of a pathway mediating the "directed delivery" of neural peptides in this nervous system.