FIGURE 5.

(A) Microphotograph of the dome of the gyrus transversus insulae (Area frontoinsularis – FJ), Nissl staining. (B) Microphotograph of the dome of the gyrus limbicus, regio anterior; frontally and dorsally from the genu corporis callosi (Area cingularis anterior – LA₂), Nissl staining. The enlarged panels show VENs in layer Vb of the FI and ACC as well as other spindle-shaped cells (Spindelzellen) and cells of ambiguous somatic morphology. Note that on Nissl staining, even in the FI and ACC, it is difficult to classify certain cells as either VENs or common modified pyramidal neurons (spindle cells, Spindelzellen). Also note the clusters of VENs in both regions as well as the relative predominance of VENs in the FI compared to the ACC. Images modified from von Economo and Koskinas (1925).