I1_MN [FBbt_00004070]

I1_MN

ID: 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).