develops from receives synaptic input in region sends synaptic output to region receives synaptic input from neuron lamina monopolar neuron L3 medulla layer M2 medulla layer M3 medulla layer M4 medulla layer M9 medulla layer M10 medulla intrinsic columnar neuron medulla intrinsic neuron Mi9 VFB:FBbt_00003784 fly_anatomy.ontology Mi9 Medulla intrinsic narrow field neuron with a bushy mix of bleb-type and fine terminal arborization in layers M2, M3 and M4 and in the lower medulla layers M9-M10 (Fischbach and Dittrich, 1989; Kind et al., 2021). It establishes pre- and post-synaptic connections in both the inner and outer medulla layers (Fischbach and Dittrich, 1989; Morante and Desplan, 2008). It receives input from lamina monopolar neuron L3 (Takemura et al., 2013). It is glutamatergic (Takemura et al., 2017). There is usually one of these cells per optic column (Nern et al., 2025). FBbt:00003784 Mi9 https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bae0/7069908/ef7abe34662d/359_2019_1375_Fig2_HTML.jpg medullary intrinsic neuron Mi9 FlyBrain_NDB:10108 Pre-synaptic terminals were assessed by labelling with a UAS-Synaptotagmin reporter (P{UAS-HA-syt} - FBtp0015803). The identification of dendrites and axons was done using a UAS-Dscam (P{UAS-Dscam.exon17.1.GFP} - FBtp0021447) or a UAS-tau (P{UAS-tau-lacZ.O} - FBtp0010033) reporter, respectively (Morante and Desplan, 2008). Connectivity in the medulla was extrapolated from serial EM from 7 columns (Takemura et al., 2013). Notch OFF hemilineage secondary neuron immature medulla intrinsic neuron Mi9 adult glutamatergic neuron optic lobe narrow field columnar neuron