receives synaptic input in region sends synaptic output to region medulla layer M1 medulla layer M2 medulla layer M3 medulla layer M4 medulla layer M9 transmedullary neuron transmedullary neuron Tm18 FBbt:00003806 FlyBrain_NDB:10141 Tm18 fly_anatomy.ontology Tm18 VFB:FBbt_00003806 Transmedullary neuron that terminates in lobula layer 4 bleb-type arborizations. It displays fine arborizations in medulla layers M1, M2m M3, M4 and M9, and has bleb-type arborizations in layers M4. Pre- versus postsynaptic innervation judged by scoring of terminal morphology from figures in Fischbach and Dittrich (1989) as assessed by FlyBrain Neuron DB. lobula layer 4