Brodmann (1909) area 4

Definition

The term area 4 of Brodmann-1909 refers to a cytoarchitecturally defined portion of the frontal lobe of the guenon. It is located predominantly in the precentral gyrus. Brodmann-1909 regarded it as topographically and cytoarchitecturally homologous to the human gigantopyramidal area 4 and noted that it occupies a much greater fraction of the frontal lobe in the monkey than in the human. Distinctive features (Brodmann-1905): the cortex is unusually thick; the layers are not distinct; the cells are relatively sparsely distributed; giant pyramidal (Betz) cells are present in the internal pyramidal layer (V); lack of an internal granular layer (IV) such that the boundary between the external pyramidal layer (III) and the internal pyramidal layer (V) is indistinct; lack of a distinct external granular layer (II); a gradual transition from the multiform layer (VI) to the subcortical white matter.

Also known as area 4 of Brodmann, area 4 of Brodmann-1909, area gigantopyramidalis, B09-4, Brodmann (1909) area 4, Brodmann area 4, Brodmann area 4, gigantopyramidal, Brodmann's area 4, giant pyramidal area — per UBERON

The Brodmann (1909) area 4 is a part of the Nervous.

Also identified as

• UMLS C1272526 per UBERON