Sagittal Silver Section X= +1.0

X= +1.0

Click on inline image to retrieve larger annotated version (approx. 250k)

The most prominent structure at this level is the ascending tract of the median bundle (m bdl), which arises from a wide root (r m bdl) that recruits fibers from suboesophageal neuropils. The m bdl also receives axons that ascend from the ventral cord [ascending tract of the median bundle (asc t m bdl)]. Axons contributing to the m bdl project each side of the esophageal foramen to converge just behind and above the most medial glomerulus of the antennal lobe (ant lob). The m bdl ascends in front of medial lobe of the mushroom body (m lo). Other central brain structures shown here include the ellipsoid body and fan-shaped body of the central complex. The superior medial protocerebral neuropils (s m pr) are prominent and are connected by the loose fasciculation of the dorsal horizontal tract (d h t). This is confluent with the posterior vertical fascicle (p ver fasc). The great commissure, linking the left and right optic lobes, is shown in cross section. Other abbreviations are: p sl, posterior slope; oc n, ocellar nerve; r lab n, root of the labial nerve; ph n, pharyngeal nerve.

The subesophageal ganglion, so-called, is actually a fusion of three neuromeres; the mandibular, maxillary, and labial, so termed after the mouthparts associated with their sensory and motor nerves, which exit the ganglia more laterally than ventrally. The mandibular neuromere is separately distinguished from the second and third segments by its punctuate texture. It also provides the pharyngeal nerves ventrally. The maxillary and labial neuromeres are clearly separated by an intermediate fiber bundle.

Flybrain    Atlas    Silver Sections    Sagittal Sections     x= +1.0

All contents are copyright © 1995-2000 Flybrain or their original publication (as noted).
Images or text may be used with proper acknowledgement.

AA00132