Figure 6. Schematic of the swim CPG and motoneurons. The rhythm is produced through reciprocal inhibitory connections between left and right swim interneurons. Each side of the brain has a pair of interneurons (I and II), that are electrically coupled. Inhibitory connections are made by the SiII's through the pedal-pedal connective. Cutting the connective blocks the rhythm. Interneurons make excitatory connection with ipsilateral motoneurons and inhibitory connections with contralateral motoneurons.