part of innervates lobula anterior optic tubercle fascicle posterior ventrolateral protocerebrum adult anterior optic tract 2010-11-30T11:51:04Z AOT FBbt:00100337 MT tract Fischbach and Lyly-Hunerberg, (1983), subdivide the anterior optic tract (AOT) into four sub-bundles: S1-S4. S1 consists of 100-110 think axons surrounded by ~60 large diameter neurons that form the S2 bundle. These bundles together occupy the proximal part of the AOT close to the neuropil of the lateral protocerebrum. S3 forms the lateral ventral part of the AOT and is formed by ~430 axons of small diameter that project into the anterior optic foci. S4 is composed of approximately 660 relatively small fibers. medulla-tubercle tract VFB:FBbt_00100337 Tract that emerges from the medial part of the lobula (Ito et al., 2014). One branch ends in the anterior optic tubercle (AOTU) whilst the other makes a medial turn to terminate in the superior medial posterior ventrolateral protocerebrum (PVLP) of the adult brain (Ito et al., 2014). It demarcates the boundaries of the PVLP (lateral region), anterior VLP (superior and lateral region), AOTU (inferior-lateral region) and lateral horn (inferior region) (Ito et al., 2014). fly_anatomy.ontology adult cerebral ganglion