| Neuron | Sensory Modality | Upstream Guanylyl Cyclase(s) | Biological Process | Key Evidence/References |
|---|---|---|---|---|
| AWC | Olfaction; volatile attractants | ODR-1, DAF-11 | Odor-evoked cGMP signaling gates TAX-2/TAX-4 to drive chemotaxis; also contributes to activity-dependent gene expression and odor plasticity | tax-2 expressed in AWC; TAX-2/TAX-4 act downstream of GPCR/G protein signaling with ODR-1 and DAF-11 in AWC olfaction (pqac-00000006, pqac-00000011, pqac-00000020) |
| ASE | Gustation; water-soluble chemicals, salt, alkalinity | GCY-14 for alkalinity; other ASE rGCs not fully specified here | Salt chemotaxis and pH/alkalinity responses require TAX-2/TAX-4-mediated cGMP signaling | tax-2 expressed in ASE; TAX-2/TAX-4 required for chemotaxis to water-soluble compounds and calcium responses to NaCl/pH changes (pqac-00000006, pqac-00000013, pqac-00000023) |
| AWB | Olfactory avoidance; volatile repellents | Not clearly resolved in the retrieved evidence; cGMP pathway upstream likely includes GPCR-regulated GC signaling | Avoidance of volatile repellents and modulation of odor responses | tax-2 expressed in AWB; TAX-2/TAX-4 required for AWB-mediated avoidance and localize to sensory cilia; PDE-5 also modulates AWB olfactory signaling (pqac-00000006, pqac-00000020, pqac-00000029) |
| AFD | Thermosensation | GCY-8, GCY-18, GCY-23 | Thermotaxis and thermotransduction through cGMP-triggered opening of TAX-2/TAX-4, causing Ca2+ fluctuations | tax-2 expressed in AFD; TAX-2/TAX-4 localized to cilia/dendrites; AFD thermosensation uses GCY-8/18/23 upstream of the channel (pqac-00000003, pqac-00000008, pqac-00000026) |
| BAG | CO2 sensing; also implicated in O2-related circuit functions | GCY-9 | CO2-evoked sensory signaling and behavioral plasticity | tax-2 expressed in BAG; recent pathway summaries place GCY-9 upstream of TAX-2/TAX-4 in BAG CO2 signaling (pqac-00000004, pqac-00000020, pqac-00000026) |
| AQR/PQR/URX | Oxygen sensing / aerotaxis | GCY-35, GCY-36 | Body-cavity neuron O2 sensing; cGMP opens TAX-2/TAX-4 to control aerotaxis | TAX-2/TAX-4 function downstream of soluble guanylyl cyclases GCY-35/36 in AQR/PQR/URX oxygen sensing (pqac-00000016, pqac-00000028) |
| ASG | Chemosensory / sensory integration | Not specified in retrieved evidence | Likely participates in TAX-2/TAX-4-dependent sensory signaling; specific pathway assignment remains limited in the retrieved literature | tax-2 expression reported in ASG, but neuron-specific upstream GC and process were not defined in the retrieved evidence (pqac-00000020) |
| ASI | Neuroendocrine chemosensory signaling | DAF-11 implicated in dauer/pheromone-related cGMP signaling | Dauer regulation, sensory integration, and regulation of daf-7 expression | tax-2 expressed in ASI; TAX-2/TAX-4 contribute to dauer-related cGMP signaling and regulation of sensory gene expression/neuroendocrine outputs (pqac-00000014, pqac-00000020) |
| ASJ | Sensory/neuroendocrine signaling; thermo/photo-related cGMP pathways in broader literature | Not clearly specified in retrieved tax-2-centered evidence | Regulation of daf-7 expression and sensory-state signaling; recent PDE literature implicates ASJ cGMP dynamics | tax-2 expression reported in ASJ; channel complex regulates gene expression including daf-7 in ASJ/ASI, but specific upstream GC was not resolved in the retrieved evidence (pqac-00000013, pqac-00000020, pqac-00000030) |
| ASK | Chemosensory / pheromone-related signaling | DAF-11 implicated in pheromone/dauer context | Dauer pheromone signaling and sensory integration | tax-2 expressed in ASK; DAF-11 and G proteins act in pheromone signaling contexts where TAX-2/TAX-4 function downstream in dauer-related pathways (pqac-00000014, pqac-00000020) |
| ADE | Sensory neuron; modality not well defined here | Not specified in retrieved evidence | tax-2 expression indicates possible CNG-dependent sensory signaling, but a precise TAX-2-specific function in ADE was not resolved in the retrieved sources | ADE listed among tax-2-expressing neurons; specific upstream GC and function not defined in retrieved evidence (pqac-00000004, pqac-00000020) |


*Table: This table summarizes where TAX-2 is expressed in C. elegans and links each neuron type to its sensory modality, likely upstream guanylyl cyclases, and major biological roles. It is useful for mapping TAX-2 onto specific cGMP-dependent sensory circuits while distinguishing well-supported assignments from areas where evidence remains limited.*