ambiguous nucleus - BrainInfo

ambiguous nucleus (AMB)

The term ambiguous nucleus refers to a long narrow group of neurons embedded in the medullary reticular formation from the spinomedullary junction to the level of the inferior olivary complex. Defined by Nissl stain, it is undivided in the human ( Koutcherov-2004 ) and the mouse ( Hof-2000 ). In the macaque some authors subdivide it into three parts: a rostral compact part of the ambiguous nucleus, an intermediate subcompact part of the ambiguous nucleus and a caudal loose part of the ambiguous nucleus ( Paxinos-2009a ). In the rat it is divided into two parts: the dorsal division of the ambiguous nucleus, one of the neuroendocrine motor zone, somatic motor neuron pools, and the ventral division of the ambiguous nucleus, one of the preganglionic autonomic pools, parasympathetic component ( Swanson-2004 ).

Also known as: nucleus ambiguus, Nucleus ambiguus, Nucleus innominatus, ambiguus nucleus, ambiguous nucleus

NeuroNames ID: 765

All Names & Sources

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English

ambiguous nucleus

NeuroNames

English

ambiguus nucleus

Bowden-1997

English

ambiguus nucleus

Carpenter-1983

English

nucleus ambiguus

Carpenter-1983

Illustrations

Showing 6 illustration(s)

myelin stain & diagram of
all aspects in
human

labeled line drawings of
sagittal section in
Macaca fascicularis

multiple views of
3D reconstruction in
Macaca mulatta

Nissl stain & diagram of
coronal section in
mouse

Nissl stain & diagram of
sagittal section in
mouse

photomicrograph of
coronal section in
primate

Species With The Structure

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

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Basis

Has Equivalent

Organism

Their Name

Source

Topology

Yes

Homo sapiens (human)

ambiguus nucleus

Carpenter-1983

Topology

Yes

Homo sapiens (human)

nucleus ambiguus

Carpenter-1983

Topology

Yes

Homo sapiens (human)

Nucleus ambiguus

Nomina-1983

Topology

Yes

Macaca fascicularis (Macaca fascicularis)

Nucleus ambiguus

Shantha-1968

Topology

Yes

Macaca mulatta (Macaca mulatta)

Nucleus innominatus

Oertel-1969

Topology

Yes

Rattus (rat)

ambiguus nucleus

Bowden-1997

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.

metabrain (metencephalon)

cisterna magna (cerebellomedullary cistern)

choroidal fissure