PHA is a set of two ciliated neurons that are components of the phasmid sensilla. Posteriorly directed processes emanate from each cell body in the lumbar ganglia and terminate in a cilium. The basal body of the cilium is ventral to that of PHB, which is also part of the same sensillum. Anteriorly directed processes enter the pre-anal ganglion via the lumbar commissures and run near the middle of the neuropile for the length of the ganglion (e). The main synaptic output is to PHB (c), AVG (a, d), PVQ (b), itself (d), DVA (a), AVF and AVH, usually in various dyadic combinations. PHA also has gap junctions to PVP (d) and itself. Magnifications : (a-d) x 25500.
Web adaptation, Thomas Boulin, for Wormatlas, 2001, 2002