has soma location fasciculates with receives synaptic input in region sends synaptic output to region supraesophageal ganglion neuron adult ellipsoid body extrinsic ring neuron adult ellipsoid body extrinsic ring neuron ExR1 helicon cell ExR1 VFB:FBbt_00003655 fly_anatomy.ontology Extrinsic ring neuron with a large soma located in the pars intercerebralis (Hanesch et al., 1989; Young and Armstrong, 2010). It follows the medial equatorial fascicle (Omoto et al., 2018) and arborizes in the dorsal fan-shaped body (FB), lateral accessory lobe (LAL) and bulb (Young and Armstrong, 2010; Omoto et al., 2018; Hulse et al., 2021). Its main projection then encircles the ellipsoid body (EB) and sends multiple evenly spaced projections that arborize in the inner central and anterior domains of the EB (Young and Armstrong, 2010; Omoto et al., 2018). Arborizations are mainly postsynaptic in the LAL (including the gall) and bulb, and mixed in the ellipsoid body and fan-shaped body (Hulse et al., 2021). There are two of these cells per hemisphere, one that develops from neuroblast DM3, and one that develops from DM4 (Kandimalla et al., 2023). ExR1 FlyBrain_NDB:10264 FBbt:00003655 Sites inferred to be presynaptic by localization of fluorescently tagged synaptobrevin and to be post-synaptic by localization of fluorescently tagged DSCAM (Young and Armstrong, 2010). fan-shaped body bulb adult pars intercerebralis ellipsoid body inner central domain gall adult medial equatorial fascicle