PDB is a single motoneuron that innervates posterior dorsal body muscles. Its cell body is situated in the posterior region of the pre-anal ganglion (d). A posteriorly directed process leaves the pre-anal ganglion via the right hand lumbar commissure (e). This then runs posteriorly, in a sub-ventral location adjacent to the right ventral muscle (b), nearly to the end of the tail. Here it turns and runs anteriorly in a mid-dorsal location (e), becoming part of the dorsal cord (the anterior end point in the dorsal cord has not been determined). The only synapses that have been seen to or from PDB are a couple of small dyadic NMJs, with DD6 as the second postsynaptic element (a). Magnifications: (a-c) x 25500, (d) x 17000.
Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002