Frontal Silver Section 10: y = 0.0

y= 0.0

Click on inline image to retrieve larger annotated version (approx. 80k)

The mushroom bodies at this level are represented only by the cross section of the pedunculus (ped; for a 3-D reconstruction of the mushroom bodies click here). Again, Kenyon cell axons, which comprise the mushroom body's intrinsic neurons, are so small that they cannot be seen individually. The occasional larger argyrophilic elements in the pedunculus represent output (efferent) neurons.

The central complex is here represented by the ellipsoid body. The bundle of converging axons described for the previous level have now penetrated the opening of the ellipsoid body. Other axons, belonging to ellipsoid body interneurons arise from this region laterally. The superior ellipsoid tract links regions of the inferior medial protocerebrum. The inferior ellipsoid tract links the two ventral bodies which are here contiguous with neuropils of the ventro-lateral protocerebrum. The anterior optic tract is visible here as the most massive and densely stained bundle of fibres, a tributary of which extends beneath the pedunculus on each side of the brain. The superior protocerebrum at this level is divided into several discrete lobe-like regions flanked laterally by the amorphous neuropil of the lateral horn.

At this level, the last glomerulus of the antennal lobe lies immediately beneath the root of the antennal glomerular tract (ant-gl.t).

Note the layered appearance of the suboesophageal ganglion. Results from filling head mechanosensory neurons in larger flies indicate that many of the layered modules are associated with specific brittle fields, suggesting an analogy with vibrissae projections to cortical barrels in rodents. Also, at this and subsequent levels, the two halves of the protocerebrum are linked by many discrete tracts, such as that arising above the +X pedunculus and extending contralaterally above the ellipsoid body. Note too, that the ventro-lateral protocerebrum is obviously subdivided into lobate regions linked by axons to other brain areas. The larger axons can easily be followed from section to section.

NJ Strausfeld, I Vilinsky, and LC Hansen, ARLDN, Tucson

Flybrain    Atlas    Silver Sections    Frontal Silver Sections    Silver Section y=+0.0

All contents are copyright © 1995-2000 Flybrain or their original publication (as noted).
Copyright and use policy

AC00034