The Tritonia swim CPG
The central pattern generator (CPG) is a neuronal circuit that produces
the pattern for rhythmical muscle movement and/or stereotyped behavior.
Left: Schematic model of the Tritonia swim central pattern generator (CPG).
Right: Location of the CPG neurons in the brain.
Dorsal Swim Interneurons (DSI), C2 neuron, Ventral Swim Interneuron B (VSI-B).
The sensory input triggers firing of Tr1, DRI and then DSI, which in turn initiates the swim motor program.
The swim motor pattern
A brief sensory stimulus produces a series of alternating bursting activities in three neurons.
DSI bursts produces dorsal body flexions whereas VSI bursts ventral body flexions.