The Mind of 
	a Worm

Member: DVA.

DVA is a single interneuron with its cell body situated in the dorso-rectal ganglion. An anteriorly directed process enters the pre-anal ganglion (i) and runs in the ventral part of the process bundle for the whole length of the ventral cord. It enters the nerve ring on the right-hand side and travels right round it in an anticlockwise direction (h) running near the centre of the neuropile in close association with the process of AQR ; it then ends shortly after rejoining the ventral cord on the left hand side. The process of DVA is generally rather large and has large, vesicle-filled varicosities in the nerve ring (b). The vesicles tend to be irregularly shaped, except in the vicinity of the presynaptic specializations, where they are smaller and more spherical (a, b). In the nerve ring the main synaptic output is to AVE (a, b, e); there are some smaller synapses to RIR (e), AVA (c), AQR (c), SMB, AIZ and AUA (b) and there are gap junctions to AVB (g). There is a little synaptic input from AIZ and SDQ (*a). In the ventral cord there are some small synapses to PVC (f), PVR, DBn (f) and VBn (d); there are several synapses from PDE (*a) and some from PHC (*c), PLM (*e), PHA (*a) and PVD (*d); there are gap junctions to PVR. Magnifications: (a, b, d, g) x 25500, (c, e, f) x 17000.

DVA ventral cord synapses
partners gap junctions synapses from synapses to and corecipients
PVC - 3m 2DB7, DB5, DB3
PDE - 22+ 14 m 1, VB11
PVR 2 - 1, DB2
DB3 - - 1, PVC
DB7 - - 2PVC
VB11 - - PDE, VA12
DB4 - - 1
VA12 - - VB11
DB2 - - PVR
DB5 - - PVC
PHC - 4+7m -
PLM - 5m -
PHA - 1+3m -
PVM - 2+1m -
AVK - 1 -

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