IL2 is a set of six ciliated neurons, each of which is one of the two component neurons of the six inner labial sensilla. The socket cell of each sensillum has a hole in it, through which the dendrite of IL2 protrudes. Processes of IL2 run posteriorly from the sensillum in each of the six labial process bundles and join their cell bodies, which are situated anterior to the ring neuropile. Posteriorly directed processes from the cell bodies rejoin the process bundles, which pass down the outside of the ring, turn and then run anteriorly (a) until the fibres disperse in the anterior regions of the neuropile. Here they run round the ring for about 60 C until they are in the vicinity of the neighbouring IL2. Thus the processes of all the IL2 inhabit most of the circumference of the ring. There are some differences in the synaptic partners of the lateral IL2 (i.e. IL2L/IL2R) from the others. The main synaptic outputs of IL2D/IL2V are to RIP (a, b), IL1D/IL1V, RME (c), URA(a), RIH (c) and OLQ; the main synaptic outputs of IL2L/IL2R are to OLQ (d), RIH (d), ADE and RME. IL2L/IL2R also have occasional dark-cored vesicles in their synapses (d) and have gap junctions with RMG and URX. Magnifications: (a, c, d) x 25500, (b) x 12750.
Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002