Inferior frontal gyrus in the context of "Brodmann area 46"

Broca's area, or the Broca area (/ˈbroʊkə/, also UK: /ˈbrɒkə/, US: /ˈbroʊkɑː/), is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production.

Language processing has been linked to Broca's area since Pierre Paul Broca reported impairments in two patients. They had lost the ability to speak after injury to the posterior inferior frontal gyrus (pars triangularis) (BA45) of the brain. Since then, the approximate region he identified has become known as Broca's area, and the deficit in language production as Broca's aphasia, also called expressive aphasia. Broca's area is now typically defined in terms of the pars opercularis and pars triangularis of the inferior frontal gyrus, represented in Brodmann's cytoarchitectonic map as Brodmann area 44 and Brodmann area 45 of the dominant hemisphere.

The primary gustatory cortex (GC) is a brain structure responsible for the perception of taste. It consists of two substructures: the anterior insula on the insular lobe and the frontal operculum on the inferior frontal gyrus of the frontal lobe. Because of its composition the primary gustatory cortex is sometimes referred to in literature as the AI/FO(Anterior Insula/Frontal Operculum). By using extracellular unit recording techniques, scientists have elucidated that neurons in the AI/FO respond to sweetness, saltiness, bitterness, and sourness, and they code the intensity of the taste stimulus.

Brodmann area 44, or BA44, is part of the frontal cortex in the human brain. Situated just anterior to premotor cortex (BA6) and on the lateral surface, inferior to BA9.

This area is also known as pars opercularis (of the inferior frontal gyrus), and it refers to a subdivision of the cytoarchitecturally defined frontal region of cerebral cortex. In the human it corresponds approximately to the opercular part of the inferior frontal gyrus. Thus, it is bounded caudally by the inferior precentral sulcus (H) and rostrally by the anterior ascending limb of lateral sulcus (H). It surrounds the diagonal sulcus (H). In the depth of the lateral sulcus it borders on the insula. Cytoarchitectonically it is bounded caudally and dorsally by the agranular frontal area 6, dorsally by the granular frontal area 9 and rostrally by the triangular part of inferior frontal gyrus (Brodmann area 45 BA 45).

Brodmann area 45 (BA45), is part of the frontal cortex in the human brain. It is situated on the lateral surface, inferior to BA9 and adjacent to BA46.

This area in humans occupies the triangular part of inferior frontal gyrus (H) and, surrounding the anterior horizontal limb of the lateral sulcus (H), a portion of the orbital part of the inferior frontal gyrus (H). Bounded caudally by the anterior ascending limb of the lateral sulcus (H), it borders on the insula in the depth of the lateral sulcus.

Brodmann area 47, or BA47, is part of the frontal cortex in the human brain. It curves from the lateral surface of the frontal lobe into the ventral (orbital) frontal cortex. It is inferior to BA10 and BA45, and lateral to BA11. This cytoarchitectonic region most closely corresponds to the gyral region the orbital part of inferior frontal gyrus, although these regions are not equivalent. Pars orbitalis is not based on cytoarchitectonic distinctions, and rather is defined according to gross anatomical landmarks. Despite a clear distinction, these two terms are often used liberally in peer-reviewed research journals.

BA47 is also known as orbital area 47. In the human, on the orbital surface it surrounds the caudal portion of the orbital sulcus (H) from which it extends laterally into the orbital part of inferior frontal gyrus (H). Cytoarchitectonically it is bounded caudally by the triangular area 45, medially by the prefrontal area 11 of Brodmann-1909, and rostrally by the frontopolar area 10 (Brodmann-1909).