AUA is a pair of neurons with cell bodies situated in the lateral ganglia. Anteriorly directed processes leave the cell bodies and run along with the bundles of processes from the amphid sensilla until they peter out, with no terminal specializations, just in front of the first bulb of the pharynx (e). A second process comes out of each cell body and enters the ventral cord via the amphidial commissures; it then turns and runs anteriorly on the ventral surface of the cord. The processes of AUA then enter and run round each side of the ring, close to the outside surface, eventually meeting and terminating in a gap junction on the dorsal mid-line. The main synaptic output is to RIB (a, b), RIA (a, c), AVE (b) and AVA (c) in various dyadic combinations. The main synaptic input is from URX (*a) and ADF. There are gap junctions to URX, AWB and AIN (d). Magnifications: (a) x 25500, (b-d) x 17000.
Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002