part of has soma location develops from capable of expresses sends synaptic output throughout has sensory dendrite in Ir21a sacculus sensillum of sacculus chamber I adult peripheral nervous system antennal olfactory receptor neuron precursor Naa antennal lobe glomerulus VP1l adult thermosensory neuron adult antennal lobe receptor neuron unilateral antennal lobe receptor neuron external sense organ sensory neuron adult thermosensory neuron Ir21a VP1l 2015-12-21T15:12:32Z https://github.com/FlyBase/drosophila-anatomy-developmental-ontology/issues/1353 Thermosensory receptor neuron that expresses the Ionotropic receptor (Ir) 21a and innervates antennal lobe glomerulus VP1l (Marin et al., 2020; Alpert et al., 2020). It has its sensory dendrite in chamber I of the sacculus and it responds to temperature drops below 25 degrees celsius (Marin et al., 2020; Alpert et al., 2020). It develops from an Naa precursor (Benton et al., 2025). There are around 6-8 of these cells per hemisphere (Marin et al., 2020) and they are unilateral (Schlegel et al., 2021). HRN_VP1l Ir21a neuron of sacculus in original reference was speculatively assigned to sacculus chamber III and VP3 (Silbering et al., 2011). Later found to be chamber I and VP1l (Marin et al., 2020 and refs therein). Assigned to 'cold glomerulus' in Alpert et al. (2020) - FBrf0246007, but projections in AL look like VP1l projections shown in Marin et al. (2020). OSN Ir21a ionotropic receptor neuron Ir21a ORN Ir21a Ir21a FBbt:00111336 HRN_VP1l adult olfactory receptor neuron Ir21a sacculus cold cell VP1lRN fly_anatomy.ontology VFB:FBbt_00111336 detection of temperature stimulus sensory perception of cold stimulus