inferior ramus of the arcuate sulcus

inferior ramus of the arcuate sulcus (iras)

The term inferior ramus of the arcuate sulcus refers to the lower, diagonal branch of the arcuate sulcus in the frontal lobe of the macaque. Defined by dissection, it separates the precentral gyrus caudally from the inferior frontal gyrus rostrally ( Martin-2000 ). Architectonically it separates the premotor cortex caudally from the dorsolateral prefrontal cortex rostrally. It may be homologous to the inferior precentral sulcus of the adult human ( See arcuate sulcus for details. ) Equivalent structures are not found in the smooth cerebral cortex of the rat or mouse ( NeuroNames ).

Also known as: Ramus inferior sulcus arcuatus, vertical arcuate sulcus, vertical ramus of arcuate sulcus, inferior arcuate sulcus, inferior ramus of the arcuate sulcus

NeuroNames ID: 65

All Names & Sources

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Showing 8 synonym(s) - Use arrows to navigate

Showing 8 synonym(s)

Name:

arc3

Language:

acronym

Organism:

Cercopithecus aethiops

Source:

Vogts-1919

Citation:

Journal für Psychologie und Neurologie, 25:1:361-376, 1919

Source Title:

Allgemeinere Ergebnisse unserer Hirnforschung. Dritte Mitteilung. Die architektonische Rindenfelderung im Lichte unserer neuesten Forschungen

Name:

Ramus inferior sulcus arcuatus

Language:

Latin

Organism:

macaque

Source:

NeuroNames

Citation:

University of Washington, Seattle, WA

Source Title:

NeuroNames

Name:

vertical arcuate sulcus

Language:

English

Organism:

Macaca mulatta

Source:

Krieg-1975

Citation:

Brain Books, Evanston, Illinois, 1975

Source Title:

Interpretive Atlas Of The Monkey's Brain

Name:

vertical ramus of arcuate sulcus

Language:

English

Organism:

macaque

Source:

Walker-1940

Citation:

Journal of Comparative Neurology, 73:59-86, 1940

Source Title:

A cytoarchitectural study of the prefrontal area of the macaque monkey

Name:

iras

Language:

acronym

Organism:

macaque

Source:

Martin-2000

Citation:

Elsevier, Amsterdam, 2000

Source Title:

Primate Brain Maps: Structure Of The Macaque Brain

Name:

inferior arcuate sulcus

Language:

English

Organism:

macaque

Source:

Matelli-2004

Citation:

Chapter 26 in The Human Nervous System, G. Paxinos and J. Mai (Eds.). Amsterdam: Elsevier Academic Press, 2004.

Source Title:

Motor Cortex

Name:

iar

Language:

acronym

Organism:

Macaca mulatta

Source:

Paxinos-2009a

Citation:

Amsterdam: Elsevier-Academic Press. 2009

Source Title:

The Rhesus Monkey Brain, Second Edition

Name:

inferior ramus of the arcuate sulcus

Language:

English

Organism:

Macaca fascicularis

Source:

Szabo-1984

Citation:

J Comp Neurol 1984 Jan 10;222(2):265-300

Source Title:

A stereotaxic atlas of the brain of the cynomolgus monkey (Macaca fascicularis)

Illustrations

Showing 3 illustration(s)

drawing of
all aspects in
human

labeled line drawings of
sagittal section in
Macaca fascicularis

drawing of
all aspects in
macaque

Species With The Structure

Equivalent By	Human	Macaque	Rat	Mouse
Topology	Relevant Data Not Located	Has The Structure	Does Not Have The Structure	Does Not Have The Structure

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Basis:

Topology

Has Equivalent:

Yes

Organism:

Macaca mulatta (Macaca mulatta)

Their Name:

vertical arcuate sulcus

Source:

Krieg-1975

Basis:

Topology

Has Equivalent:

Organism:

Rattus (rat)

Their Name:

---

Source:

NeuroNames

Basis:

Topology

Has Equivalent:

Organism:

Mus (mouse)

Their Name:

---

Source:

NeuroNames

Models Where It Appears

Structural CNS Model - Macaque

Brain structures of the macaque are illustrated in BrainInfo’s NeuroMaps macaque brain atlas. Structures are grouped by proximity in a hierarchy corresponding to the central nervous system hierarchy of NeuroNames ( Bowden-1995 Martin-2000 ). Structures in the NeuroMaps atlas are based on the segmentation of an MRI of the brain of a 3-year old male rhesus macaque (Macaca mulatta). The atlas is most useful for targeting structures for implantating electrodes and chemtrodes. Updated 29 Oct 2025.

brain

forebrain

endbrain

cerebral cortex (cortical plate)