Type: Interneuron
In MoW: AIA
In Worm Wiring: AIAL _h, AIAR _h, AIAL_m, AIAR _m
In Wormbase: AIA, AIAL, AIAR
Lineage: AB plppaappa, AB prppaappa
Location: Ventral ganglion in the head
Description: Ring interneurons. AIAL and AIAR are located anteriorly to the excretory cell, at the ventral side of the terminal bulb of pharynx. They are located very close to each other on the right and left sides of the A-P midline.The process of each AIA neuron entes the nerve ring from the ventral side, runs dorsally and meets its contralateral partner at the dorsal midline and makes a gap junction with it
Neurotransmitter/ Neuropeptide:
- Acetylcholine
- FLP-1; FMRFamide-like neuropeptide
- FLP-2; FMRFamide-like neuropeptide
- INS-1; insulin-like peptide. Important in the neuropeptide feedback loop between

AWC and AIA.
(Chalasani et al., 2010; Li and Kim, 2008; Altun-Gultekin et al., 2001; Nelson et al., 1998)
Innexin expression:
None yet reported, although described to have gap junctions in adult animals (MoW)
Receptor expression:
- GLR-2; AMPA-type ionotropic (Na⁺/K⁺) glutamate receptor subunit
- GLC-3; L-glutamate-gated chloride channel subunit (ionotropic glutamate rec subunit). AWC-AIA synapse is an inhibitory, glutamatergic synapse via GLC-3, whose function is acutely modulated by NLP-1/NPR-11 signaling
- GCY-28; transmembrane receptor guanylate cyclase
- MGL-1; group II metabotropic glutamate receptor
- NPR-5; receptor for FLP-18 peptides
- NPR-11; candidate receptor for NLP-1
- SCD-2; ALK receptor tyrosine kinase
- SRA-11; G protein-coupled seven transmembrane receptor
(Wormbase; Altun, 2011; Shinkai et al, 2011; Chalasani et al., 2010; Glauser and Goodman, 2010; Greer et al, 2008; Altun-Gultekin et al., 2001; Brockie et al., 2001)
Function: Integration of information from amphid sensory neurons; AIA pair is one of the four (AIA, AIB, AIY, and AIZ) first layer amphid interneuron pairs that receive and process synaptic output from the amphid sensory neurons towards a behavioral response. AIA pair is suggested to sum inputs from various chemosensory neurons before passing the information on to AIB pair, which synapses onto motor neurons (AIA-AIB connections are likely to be inhibitory) (Wakayabashi et al., 2004). AIA neurons are the main target of ASI outputs.
- AIA interneurons integrate multiple sensory cues to adjust behavioral choices and play an important role in learning (e.g. salt chemotaxis learning) and behavioral plasticity (Shinkai et al, 2011; Tomioka et al., 2006).
- Functions in locomotion: in isothermal tracking, AIB and AIZ interneurons promote turns while AIY and AIA interneurons inhibit turns (Garrity et al., 2010).
- The AIA neurons play a role in chemotaxis to ascarosides, downstream of the ASK sensory neuron (Srinivasan et al., 2012, Macosko et al., 2009).