Brodmann area 13


Brodmann area 13 is part of the insula, a subdivision of the cerebral cortex as defined by cytoarchitecture. The insula is covered by frontal, temporal and parietal operculum and therefore sometimes ignored as a Brodmann area.

Location

Located in the anterior part of the insular cortex, Brodmann area 13 shares with other parts of the insular cortex a wide molecular layer and very wide multiform layer.

Layers

The external granular layer is relatively dense. The external lamina pyramidalis externa has a central stripe of less cellular density that separates two sublayers, IIIa and IIIb. The internal granular layer is sufficiently wide and dense to separate clearly sublayer IIIb from layer V. The boundary between layers V and VI is defined by larger ganglion cells, more pyramidal in shape, in layer V giving way to smaller, more spindle-shaped cells that become denser and more homogeneous deeper in layer VI. Often the spindle cells are arrayed horizontally as in the claustrum, which Brodmann considered a likely extension of layer VI beyond the extreme capsule .