Type: Sensory neuron (putative proprioceptive)
Male Wiring Project: PHD
In Wormbase: PHD
Lineage: PHso1L, PHso1R
Location: Right and left lumbar ganglia in male tail
Description: Male-specific ciliated putative proprioceptive sensory neurons. Post-embryonically born in males at L4 by glia-to-neuron transdifferentiation of the Phso1 cell (Molina-Garcia et al., submitted)
Neurotransmitter/ Neuropeptide:
- Acetylcholine
Innexin expression:
Receptor expression:
Function:
- They become part of male-specific circuits for copulation. These neurons ensure coordinated backward movement along the hermaphrodite’s body during mating, and regulate execution of an alternative readjustment movement performed when intromission becomes difficult to achieve.

They are purported to become activated by tail tip deformations and engage the circuits for backward locomotion possibly through activation of their postsynaptic partners EF, PVX, PVY neurons (Molina-Garcia et al., submitted, Cook et al, 2019.) Their structure is variable in the adult male, sometimes showing 0, 1 or 2 cilia, with or without several AFD-like villi emanating from the basal body. The PHD cilia can differ also in final position, coming to lie in variable places with respect to the other phasmid ciliated endings; they can be more central, dorsal, ventral, or lateral than the endings of PHA and PHB (Hall, D.unpublished observations, 2019.) They are considered to be cholinergic (UNC-17-expression) and peptidergic (IDA-1-expression) (Molina-Garcia et al., submitted)