has soma location fasciculates with develops from capable of part of sends synaptic output to region adult ellipsoid body ring neuron adult lateral ellipsoid fascicle ellipsoid body adult ellipsoid body R-neuron Ring neuron that develops from the DALv2 neuroblast during the larval stage (Lovick et al., 2017; Omoto et al., 2018; Bridi et al., 2019). Its small soma is located in a cluster just dorsolateral to the antennal lobe and ventrolateral to the lateral accessory lobe (LAL) (Hanesch et al., 1989). There are approximately 150 R-neurons per hemisphere, making them more abundant than the extrinsic ring neurons (Omoto et al., 2018). They have projections that extend dorsoposteriorly, branching off localized neurites with postsynaptic terminals into the bulb or, less frequently, the LAL (Young and Armstrong, 2010; Omoto et al., 2018). They enter the lateral ellipsoid fascicle, and via a circular process, terminate medially into the ellipsoid body (EB) (Omoto et al., 2018). In the EB, distal neurites of R-neurons either project centrifugally (inside-out) or centripetally (outside-in) (Omoto et al., 2018) and have presynaptic terminals there (Young and Armstrong, 2010). They are GABAergic (Bridi et al., 2019). All subtypes have functions in regulating sleep (Yan et al., 2023). dorsal cluster Poxn-neuron FBbt:00007507 ER Sites inferred to be presynaptic by localization of fluorescently tagged synaptobrevin and to be postsynaptic by localization of fluorescently tagged DSCAM (Young and Armstrong, 2010). R neuron R-cell DC Poxn-neuron R-neuron ring neuron R VFB:FBbt_00007507 ER-neuron fly_anatomy.ontology LTR-EB ER RF tract secondary neuron neuroblast DALv2 adult EBa1 lineage neuron larval ellipsoid body R-neuron precursor adult GABAergic neuron adult anterior brain cell body rind sleep