]> T4 neuron Pre- versus postsynaptic innervation judged by scoring of terminal morphology from figures in Fischbach and Dittrich (1989) as assessed by FlyBrain Neuron DB. The neurotransmitter was assessed with a split-GAL4 strategy using a Chat-DBD allele (FBal0198074) (Mauss et al., 2014) and single-cell transcript profiling (Shinomiya et al., 2014). T4 VFB:FBbt_00003731 T4 T neuron T4 fly_anatomy.ontology FBbt:00003731 T neuron with its cell body posterior to the lobula plate and a cell body fiber that projects through the lobula plate and via the second optic chiasma, with little or no arborization, to medulla layer 10 (Fischbach and Dittrich, 1989; Shinomiya et al., 2019). It forms a fine arborization in medulla layers M9 and M10 and its axon then doubles back across the second optic chiasma to form bleb-type arborizations in a single layer of the lobula plate (Fischbach and Dittrich, 1989; Shinomiya et al., 2019). It is a cholinergic neuron (Mauss et al., 2014; Shinomiya et al., 2014). There are a large number of these cells, which are generated from neuroblasts that amplify by symmetric division (type III) before generating the T4 (and T5) neurons (Mora et al., 2018). https://cdn.ncbi.nlm.nih.gov/pmc/blobs/bae0/7069908/ef7abe34662d/359_2019_1375_Fig2_HTML.jpg cell body rind of adult posterior lobula plate lobula plate layer has soma location immature T4 neuron develops from adult cholinergic neuron receives synaptic input in region sends synaptic output to region T neuron medulla layer M9 medulla layer M10 secondary neuron