The Mind of 
	a Worm

Member: DVB.

WA editors' note: Later studies have shown that in the anterior half of the animal the process that was originally attributed to DVB is actually that of PVT, and vice versa. Hence, it is not the DVB axon but the PVT axon that reaches the nerve ring, and the connections that were attributed to DVB axon are actually those of PVT (WBG 16(1):24 (October 1, 1999))

DVB is a single interneuron/motoneuron with its cell body situated in the dorso-rectal ganglion. An anteriorly directed process enters the ventral cord and runs in the dorsal regions of the process bundle until the nerve ring is reached. This then enters the nerve ring close to the ventral mid-line and runs right round it in a clockwise direction on the outside surface of the neuropile. At all times along its length, the process of DVB runs in close association with that of DVC. In the nerve ring the main synaptic output is to AVK (b), AIE (a), RMF (a), DVC and RIG and there are gap junctions to AVK, RIB and AIB. The synaptic activity in the ventral cord is restricted to the pre-anal ganglion, where there are NMJs to the intestinal and anal depressor muscles (c), and also synapses to the rectal epithelial cell (d), AVL, DA8, DD6, PDA and DVC. Some of the presynaptic endings in the nerve ring have a few dark-cored vesicles (b). There is a gap junction to AVL. Magnifications: (a, c, d) x 25500, (b) x 17000.
DVB ventral cord synapses
partners gap junctions synapses from synapses to and corecipients
NMJ - - 4, DA8
HDC - - 2, 3 DVC
AVL 1 - 2 DD6, PVP
DVC - - 3 HDC
DD6 - - 2AVL, DA8
DAB - - DD6, NMJ
PVP - - 1, AVL
VC2 - 2m -
AVG - 1 -
VA9 - 1m -
AVE - 1m -
VC5 - 1m -
PVQ - 1m -

Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002