intermediate sensillum of antennal segment 3 antennal intermediate sensillum ai3 antennal intermediate sensillum I3 FBbt:00067000 antennal intermediate sensillum ai2 I-3 sensillum Olfactory intermediate sensillum of antennal segment 3 that houses the dendrites of three olfactory receptor neurons, expressing Or2a, Or19a and Or43a (Grabe et al., 2016). antennal trichoid sensillum at3 VFB:FBbt_00067000 Reclassified from trichoid to intermediate by fluorescence-guided single sensillum recording (FG-SSR) (Lin and Potter, 2015; https://orcid.org/0000-0002-1373-1705). Dweck et al. (2013) - FBrf0223680 refer to this as ai2, but show presence of three neurons with one expressing Or19a. fly_anatomy.ontology