A cranial nerve nucleus is a collection of neuron cell bodies (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 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, 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. More lateral, but also less posterior, are the general somatic afferent nuclei. This is the trigeminal nucleus. 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 (IX) Superior salivary nucleus (VII) Facial nucleus (VII) - motor Abducens nucleus (VI) - motor Trigeminal motor nucleus (V) - motor Main trigeminal nucleus (V) - sensory (fine touch and vibration)
Hypoglossal nucleus (XII) - motor Dorsal motor nucleus of vagus nerve (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
+ Nuclei of the cranial nerves Olfactory nerve Olfactory bulb Optic nerve Lateral geniculate nucleus Oculomotor nerve Oculomotor nucleusEdinger-Westphal nucleus Trochlear nerve Trochlear nucleus Trigeminal nerve Trigeminal nerve nuclei:Mesencephalic nucleusPrincipal sensory nucleusSpinal trigeminal nucleusTrigeminal motor nucleus Abducens nerve Abducens nucleus Facial nerve Facial motor nucleusSuperior salivatory nucleusSolitary nucleus Vestibulocochlear nerve Vestibular nucleiw. subnucleiCochlear nucleusw. subnuclei Glossopharyngeal nerve Solitary nucleusSpinal nucleus of the trigeminal nerveLateral nucleus of vagal trigone.Nucleus ambiguusInferior salivatory nucleus Vagus nerve Dorsal nucleus of vagus nerveNucleus ambiguusSolitary nucleusSpinal trigeminal nucleus Accessory nerve Spinal accessory nucleusNucleus ambiguus Hypoglossal nerve Hypoglossal nucleus
References Lennart Heimer, The Human Brain,
Additional images
External links
Slides at Colorado College