Type: Sensory neuron (proprioceptive), motor neuron
Male Wiring Project:
In Wormbase: SPC, SPCL, SPCR
Lineage: B.alpaap, B.arpaap
Location: Cloacal ganglia (L), Cloacal ganglia (R)
Description: One of 3 bilateral pairs of male specific neurons (SPCL/R, SPDL/R, SPVL/R) that innervate the the left and right male copulatory spicules. Along with P.C.S. neurons, SPCL/R also innervate the male gonad (Jarrell et al., 2012; Male Wiring Project). SPCL/R are thought have both sensory (proprioceptive) and motor function. The dendrite of SPCL/R attaches to the dorsal spicule protractor muscles (dspL/R) via hemidesmosomes and the axon has outputs onto the dorsal and ventral protractor (vspL/R) muscles (Sulston et al., 1980)
Neurotransmitter/ Neuropeptide:
- Acetylcholine
- FLP-3; FMRFamide-like neuropeptide
(Garcia et al., 2001; C. Li, M. Barr, pers. comm.)
Innexin expression:
Receptor expression:
- SPC neurons innervate the protractor muscles (dspL/R and vspL/R) and have a sensory projection that is attached to the base of the spicules. When the spicules partially penetrate the vulval slit during prodding while mating, SPC neurons likely sense the change in spicule position. They then induce full insertion of the spicules into the vulva by promoting prolonged, tonic contraction of dspL/R and vspL/R.
(Liu et al, 2011; Garcia et al., 2001; Liu and Sternberg, 1995; see Mating Movie and Spicule Muscle Contraction Movie)
- Along with P.C.S. neurons PCA and PCB, SPC may regulate sperm movement. Ablation of PCB along with SPC decreases sperm ejaculation significantly. The remaining sperm release may be due to PCA (LeBoeuf et al., 2014)

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