has characteristic has soma location fasciculates with has synaptic IO in region sends synaptic output to cell mesothoracic neuron muscle cell of wing axillary muscle I1 adult anterior dorsal mesothoracic nerve direct flight muscle motor neuron wing axillary muscle I1 motor neuron I1mn I1_MN I1_MN fly_anatomy.ontology FBbt:00004070 VFB:FBbt_00004070 Motor neuron that innervates the muscle of first axillary 53 (I1), ipsilaterally (Trimarchi and Schneiderman, 1994). It has a roughly spherical soma, found ventral to the point at which the posterior dorsal mesothoracic nerve exits the ventral nerve cord (Trimarchi and Schneiderman, 1994). Its axon exits the ventral nerve cord in the anterior dorsal mesothoracic nerve (Trimarchi and Schneiderman, 1994). It has a large, medially-directed neurite that branches just before reaching the midline. One branch projects ventrally, close to the midline, another arborizes dorsal to the medial region of the mesothoracic leg neuropil with some extensions into the root of the dorsal metathoracic (haltere) nerve, and another forms arbors in the anterior and posterior wing neuropil (Trimarchi and Schneiderman, 1994). Its central arbors remain ipsilateral (Trimarchi and Schneiderman, 1994; Ehrhardt et al., 2023). wing neuropil adult dorsal metathoracic nerve root cell body rind of adult mesothoracic neuromere unilateral