RID is a single motoneuron that innervates dorsal body muscles. Its cell body is situated in the dorsal ganglion on the dorsal mid-line. A single process emanates from the ventral side of the cell body and runs down one side of the nerve ring and enters the neuropile of the ventral ganglion. In the N2U series, this process was on the left-hand side; in the JSH series, it ran to the right. The process then leaves the ventral cord via the amphidial commissure and runs round to the dorsal cord. Here it meets a short process that has come directly from the cell body and has a gap junction with it (d). RID probably runs along the length of the dorsal cord. It has not been followed for the whole length but its process has been identified in the posterior regions of the cord on the basis of the morphology of its synapses. RID has a few, rather small, synapses, which are all in the dorsal cord. These are mainly to hypodermal cells (a), DDn motor neurons (b) and dorsal muscles. The synaptic input is from PVC in the nerve ring. Gap junctions are made to AVB (c) and ALA (*c). Magnifications: (a-d) x 25500.
Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002