Nonimpulse-mediated synaptic transmission during the generation of a cyclic motor program.

A small neuronal network in the lobster stomatogastric ganglion, composed of impulse-producing motor neurons, gives rise to cyclic patterned outputs. This network continues to generate its cyclic motor program if impulse production within the ganglion is blocked. Continuously graded, nonimpulse-mediated, chemical synaptic transmission is suffucient to coordinate neuronal activity in a functioning pattern generator.