develops from receives synaptic input in region sends synaptic output to region medulla layer M1 distal medullary amacrine neuron distal medullary amacrine neuron Dm1 Dm1 FlyBrain_NDB:10081 Pre- versus postsynaptic innervation judged by scoring of terminal morphology from figures in Fischbach and Dittrich (1989) as assessed by FlyBrain Neuron DB. FBbt:00003768 fly_anatomy.ontology Distal medullary wide-field amacrine neuron whose cell body is located in the anterior region of the cell body rind of the medulla. It branches extensively at the distal surface of the medulla forming a moderately broad arbor with each branch making a distinctive bouton-like terminal in the region between M1 and M2 (in the same sublayer as Dm18, and more proximal than Dm9 and Dm10 in M1), from which short, fine terminal branches project (Morante and Desplan, 2008; Fischbach and Dittrich, 1989). The arbor varies in shape between cells, covering around 20-30 columns, but with these areas overlapping. The size of the terminals of Dm1 is smaller than those of Dm18. There are around 40 Dm1 neurons per hemisphere. They are glutamatergic (Davis et al., 2020). Dm1 VFB:FBbt_00003768 Notch OFF hemilineage secondary neuron immature distal medullary amacrine neuron Dm1 adult glutamatergic neuron