Type: Sensory neuron (chemosensory, odorsensory, pheromone-sensory, nociceptive)
Connectivity:
- In MoW: ADL
- In Nemanode: ADL
In Wormbase: ADL, ADLL, ADLR
Lineage: AB alppppaad, AB praaapaad
Location: Lateral ganglia in the head
Description: Amphid neurons, dual (AdL) ciliated sensory endings. Like all other amphid neurons, ADL are born near the presumptive nose of the embryo during development. They then anchor a short projection there, after which the cell body migrates away, stretching the dendrite out behind it. This process is dependent on DEX-1 or DYF-7, secreted extracellular matrix proteins which act cooperatively for anchoring. In mutants lacking these proteins, the dendrite fails to anchor at the nose and is dragged along with the migrating cell body, giving rise to a short dendritic stub (Heiman and Shaham, 2010). Dendritic process takes up FITC. Each ADL axon enters the nerve ring from the lateral side directly and runs both dorsally and vertrally within the ring. The dorsal branch meets its contralateral partner at the midline and makes a gap junction with it. Sister cells of ADL neurons undergo apoptosis.

Neurotransmitter/ Neuropeptide:
- Glutamate
- FLP-4; FMRFamide-like neuropeptide
- FLP-21; FMRFamide-like neuropeptide
- NLP-7; neuropeptide-like peptide
- NLP-8; neuropeptide-like peptide
- NLP-10; neuropeptide-like peptide
(Li and Kim, 2008; Rogers et al., 2003; Nathoo et al., 2001; O. Hobert, pers. comm.)
Innexin expression:
- CHE-7
- INX-1a
- INX-1b
- INX-7
- INX-10a
- INX-14
- INX-18a
- INX-19
- UNC-7
- UNC-9
(Altun et al., 2009; Bhattacharya et al., 2019; Chuang et al., 2007; Liu et al., 2006)
Receptor expression:
- GCY-21; transmembrane receptor guanylate cyclase
- OSM-9; TRPV (transient receptor potential channel, vanilloid subfamily; mammalian capsaicin receptor-like channel)-cation selective
- OCR-1; TRPV (transient receptor potential channel, vanilloid subfamily; mammalian capsaicin receptor-like channel)
- OCR-2; TRPV (transient receptor potential channel, vanilloid subfamily; mammalian capsaicin receptor-like channel)
- SER-6; octopamine receptor
- SRB-6; G protein-coupled seven transmembrane receptor
- SRE-1; G protein-coupled seven transmembrane receptor
- SRH-132; G protein-coupled seven transmembrane receptor
- SRH-220; G protein-coupled seven transmembrane receptor
- SRI-51; G protein-coupled seven transmembrane receptor
- SRO-1; G protein-coupled seven transmembrane receptor
- TMC-1; putative cation channel, salt-sensing receptor
(Wormbase; Chatzigeorgiou et al., 2013; Mills et al., 2012; Altun, 2011; Tobin et al., 2002; de Bono et al., 2002; Colbert et al., 1997; Troemel et al., 1995)
Function:
- ASH, ADL, ASK and ASE sensory neurons are responsible for the detection of certain chemical repellents. ASH plays a major role in this avoidance, whereas ADL, ASK and ASE play minor roles that are only evident when ASH is missing (de Bono and Maricq, 2005; Hiliard et al., 2002; Sambongi et al., 1999; Bargmann et al., 1990). ADL mediate avoidance behavior from heavy metals (Cd⁺⁺ and Cu⁺⁺⁾ (Sambongi et al., 1999), odors (e.g. octanol) (Troemel et al., 1995), high osmotic strength and SDS.
- Balances between at least four sensory cell types, ASE, ASI, ASH, ADF and perhaps ADL, modulate the response to NaCl (Hukema et al, 2006).
- ASH and ADL are proposed to mediate social feeding behavior in response to repulsive cues (e.g. high O₂ levels); ablation of ASH and ADL abolishes social feeding behavior transforming social animals to solitary feeders; avoidance of high O₂ levels that facilitate aggregation is promoted by OCR-2 and OSM-9, and the transmembrane protein ODR-4, acting in the nociceptive neurons ASH and ADL. ASH and ADL, in turn, transmit information about aversive stimuli in the environment to a circuit that is responsible for aggregation, rapid locomotion, and food bordering behavior (Rogers et al., 2006; de Bono et al., 2002).
- Sense pheromone and are involved in behavioral responses to pheromone (C. elegans pheromone is a mixture composed of derivatives of the dideoxysugar ascarylose [C3, C6, C7, C9 and other ascarosides] that regulates entry to dauer stage at L1, as well as adult behaviors such as sexual attraction of males to hermaphrodites and social behavior, i.e., attraction between hermaphrodites to clump into feeding groups) (Jang et al., 2012; Lockery, 2009; Macosco et al., 2009).
Reporters:
- At CGC: OH14884 otIs646 [srh-127p::GFP + pha-1(+)] (Masoudi et al., 2018).
- Other: