A cranial nerve nucleus is a collection of neurons ( gray matter) in the brain stem that is associated with one or more of the cranial nerves. Axons carrying information to and from the cranial nerves form a

synapse In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to the transmission of nervous impulses from ...

first at these nuclei. Lesions occurring at these nuclei can lead to effects resembling those seen by the severing of nerve(s) they are associated with. All the nuclei except that of the trochlear nerve (CN IV) supply nerves of the same side of the body.

Structure

Motor and sensory

In general, motor nuclei are closer to the front ( ventral), and sensory nuclei and neurons are closer to the back ( dorsal). This arrangement mirrors the arrangement of tracts in the spinal cord. * Close to the midline are the

motor efferent nuclei The general (spinal) somatic efferent neurons (GSE, somatomotor, or somatic motor fibers), arise from motor neuron cell bodies in the ventral horns of the gray matter within the spinal cord. They exit the spinal cord through the ventral roots, carr ...

, such as the oculomotor nucleus, which control skeletal muscle. Just lateral to this are the autonomic (or visceral) efferent nuclei. * There is a separation, called the sulcus limitans, and lateral to this are the sensory nuclei. Near the sulcus limitans are the visceral afferent nuclei, namely the

solitary tract nucleus In the human brainstem, the solitary nucleus, also called nucleus of the solitary tract, nucleus solitarius, and nucleus tractus solitarii, (SN or NTS) is a series of purely sensory nuclei (clusters of nerve cell bodies) forming a vertical column ...

. * More lateral, but also less posterior, are the general somatic afferent nuclei. This is the

trigeminal nucleus The sensory trigeminal nerve nuclei are the largest of the cranial nerve nuclei, and extend through the whole of the midbrain, pons and medulla, and into the high cervical spinal cord. The nucleus is divided into three parts, from rostral to caud ...

. Back at the dorsal surface of the brainstem, and more lateral are the special somatic afferents, this handles sensation such as balance. * Another area, not on the dorsum of the brainstem, is where the special visceral efferents nuclei reside. These formed from the pharyngeal arches, in the embryo. This area is a bit below the autonomic motor nuclei, and includes the nucleus ambiguus, facial nerve nucleus, as well as the motor part of the trigeminal nerve nucleus.

Location

This list documents nuclei by the part of the brain they are found in: * Red nucleus - motor, extrapyramidal * Trochlear nucleus (IV) - motor * Oculomotor nucleus (III) - motor * Edinger-Westphal nucleus (III) - visceromotor * Cochlear nuclei (VIII) - sensory ** Dorsal cochlear nucleus ** Ventral cochlear nucleus * Vestibular nuclei (VIII) - sensory * Salivary nuclei - visceromotor **

Inferior salivary nucleus The salivatory nuclei are the superior salivatory nucleus, and the inferior salivatory nucleus that innervate the salivary glands. They are located in the pontine tegmentum in the brainstem. They both are examples of cranial nerve nuclei. The su ...

(IX) ** Superior salivary nucleus (VII) * Facial nucleus (VII) - motor * Abducens nucleus (VI) - motor *

Trigeminal motor nucleus The trigeminal motor nucleus contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid, and anterior belly of the digastric. This nucleus is l ...

(V) - motor * Main trigeminal nucleus (V) - sensory (fine touch and vibration) Medulla oblongata - posterior - low mag

* Hypoglossal nucleus (XII) - motor *

Dorsal motor nucleus of vagus nerve The dorsal nucleus of vagus nerve (or posterior nucleus of vagus nerve or dorsal vagal nucleus or nucleus dorsalis nervi vagi or nucleus posterior nervi vagi) is a cranial nerve nucleus for the vagus nerve in the medulla that lies ventral to the ...

(X) - visceromotor * Nucleus ambiguus (IX, X, XI) - motor * Solitary nucleus (VII, IX, X) - sensory * Spinal trigeminal nucleus (V) - sensory (crude touch, temperature and pain) * Inferior olivary nucleus afferent fibres to cerebellum

Location

References

Lennart Heimer Lennart Heimer (11 March 1930 – 12 March 2007), was a Swedish-American neuroscientist and professor at the Massachusetts Institute of Technology and the University of Virginia. He was most noted for mapping circuits of the brain in the limbic lobe ...

, ''The Human Brain'',

Additional images

File:Gray697.png, Nuclei of origin of cranial motor nerves schematically represented; lateral view. File:Gray698.png, Primary terminal nuclei of the afferent (sensory) cranial nerves schematically represented; lateral view. File:Brain stem sagittal section.svg, Brain stem sagittal section

External links

*
Slides at Colorado College
{{Authority control Brainstem