Brodmann area 15

Brodmann area 15 is a subdivision of the cerebral cortex of the guenon defined on the basis of cytoarchitecture. It is located in the part of the insula nearest the limen of insula. The cortex is somewhat thinner with less cellular density than in other parts of the insula. The molecular layer (I) is unusually wide; the external granular layer (II) and the external pyramidal layer (III) are less dense, and the internal granular layer (IV) is totally absent, so that the medium-sized pyramidal cells of layer III and the internal pyramidal layer (V) merge with a few isolated granular cells scattered at their boundary. The multiform layer (VI) divides into a more densely cellular outer sublayer (VIa) and a less dense inner sublayer (VIb). As in Brodmann area 14-1905, the sublayer VIb merges with the adjacent claustrum. The cells in all of layer VI form tangential rows similar to the formation seen in area 10 of Brodmann-1909 and area 11 of Brodmann-1909 (Brodmann-1905)