receives synaptic input in region sends synaptic output to region receives synaptic input from neuron sends synaptic output to cell lamina lamina monopolar neuron L1 lamina monopolar neuron L2 columnar neuron T1 optic lobe centrifugal columnar neuron centrifugal neuron C3 Pre-synaptic terminals were assessed by labelling with a UAS-Synaptotagmin reporter (P{UAS-HA-syt} - FBtp0015803). The identification of dendrites was done using a UAS-Dscam (P{UAS-Dscam.exon17.1.GFP} - FBtp0021447) reporter (Morante and Desplan, 2008). Cell connectivity in the lamina was determined by analysis of semi-automated EM reconstruction of 749 serial sections of 21 complete lamina cartridges. Connectivity in the medulla was extrapolated from serial EM of 7 columns from a single sample (Takemura et al., 2013). Adult centrifugal neuron with arborizations in medulla layers M1-2, M5, and M9-10 and more restricted arborizations in the lamina (Fischbach and Dittrich, 1989; Kind et al., 2021). It forms presynapses and postsynapses in the lamina (Morante and Desplan, 2008; Rivera-Alba et al., 2011). In the medulla it is strongly presynaptic to monopolar lamina neuron L2 and columnar neuron T1, and strongly postsynaptic to L1 (Takemura et al., 2013). It is GABAergic (Fei et al., 2010). There is usually one of these cells per optic column (Nern et al., 2025). VFB:FBbt_00003744 C3 FBbt:00003744 fly_anatomy.ontology C3 FlyBrain_NDB:10080 medulla layer M1 medulla layer M2 medulla layer M5 medulla layer M9 medulla layer M10 adult GABAergic neuron optic lobe wide-field columnar neuron