part of overlaps adult thorax adult ventral nerve cord tectulum 2018-03-27T16:42:29Z Tct fly_anatomy.ontology flight neuropil VFB:FBbt_00007727 FBbt:00007727 tect T The tectulum is a distinct subdivision of the thoracic regions of the ventral nerve cord (VNC) (Power, 1948). The region forms a saddle-like structure located dorsally, primarily over the accessory mesothoracic neuropil, spanning the mesothoracic neuromere (MesoNm), and extending into the posteriormost region of the prothoracic neuromere (ProNm) and the anteriormost region of the metathoracic neuromere (MetaNm) (Power, 1948). Its internal boundaries within the VNC can be defined as the dorsal region of the neuropil posterior to the ventral ellipse in the ProNm, but dorsal to the bundles from 12B, 6B, 23 17, 18B in the MesoNm (Shepherd et al., 2016; Court et al., 2020). It extends posteriorly through the MesoNm to the entry point of hemilineage 3A in the MetaNm (Shepherd et al., 2016). It is stratified into the upper, intermediate and lower tectulum (Namiki et al., 2018; Court et al., 2020). synaptic neuropil block adult prothoracic neuromere adult mesothoracic neuromere adult metathoracic neuromere