Figure 1.

Diagram showing neural pathways involved in the initiation and stopping of tadpole swimming. Synaptic connections are drawn with symbols representing electrical coupling and the use of different neurotransmitters. Question marks indicate uncertainty in connections. Abbreviations are: p - pineal photoreceptor; pg - pineal ganglion cell; d/md - diencephalic/mesencephalic descending interneuron; TG - trigeminal ganglion cell; mhr – mid-hindbrain reticulospinal neurons; dIN - descending interneurons, cIN - commissural interneurons; MN - motoneuron; aIN - ascending interneurons; dla - dorsolateral ascending interneurons; dlc - dorsolateral commissural interneurons; RB - Rohon-Beard cells. The tadpole swimming CPG includes dIN, cIN, aIN and MN (Figure courtesy of Alan Roberts and modified with permission).