AVM and PVM
The Mind of 
	a Worm

Members: AVM, PVM.

AVM and PVM, although given separate class names, have been grouped together because of their many common features. Both are known to be touch receptors (Chalfie & Sulston 1981) and share with ALM and PLM the large microtubules that are present on the regions of their processes which are adjacent to the cuticle (Chalfie & Thomson 1982). The cell body of PVM is situated laterally, on the left-hand side of the posterior half of the body (i). A process from the cell body enters the ventral cord via a commissure and runs anteriorly along it in an extreme ventral location adjacent to the cuticle. It terminates in the anterior body after making some en passant synapses, mainly to AVK (f), PDE (g), PVC (h) and PVR. There are gap junctions to PDE and AVL (*d). The cell body of AVM is situated laterally, on the right-hand side of the anterior half of the body (i). A process leaves the cell body and enters the ventral cord via a commissure, and then runs anteriorly along it in an extreme ventral location, alongside the process of PVM. It terminates at a position just beyond the first bulb of the pharynx. A branch leaves the main process and enters the neuropile of the ventral ganglion. This splits and the branches enter the nerve ring at each side, but terminate, while still in the ventral half of the ring, with gap junctions to the ends of the processes of ALM. Nearly all the synapses of AVM are on these branches. The main synaptic output is to AVB (a), PVC (a), BDU (b), ADE (c) and PVR. AVM has gap junctions with ALM (d) and AVD (e). Magnifications: (a, b, d, e) x 25500, (c, f-h) x 17000.


AVM ventral cord synapses
Partners gap junctions synapses from synapses to and corecipients
ADE - - 1, DA1
DA1 - - ADE
AVD - - -
PVM - 1m -
AVK - 1m -


PVM ventral cord synapses
partners gap junctions synapses from synapses to and corecipients
AVK - 1 7, AVM, PVR, PDE, DVA
PDE 2 2m 3, 5 PDE, AVK, PVR
DVA - - 1, AVK, HDC
PVC - - 2
PVR - - PDE, AVK
AVM - - AVK
HDC - - DVA
AVL 1 - -


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