Neural - Cranial Nerve Development
|Embryology - 31 May 2020 Expand to Translate|
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|A personal message from Dr Mark Hill (May 2020)|
|contributors to the site. The good news is Embryology will remain online and I will continue my association with UNSW Australia. I look forward to updating and including the many exciting new discoveries in Embryology!|
- 1 Introduction
- 2 Some Recent Findings
- 3 Neural Development Overview
- 4 Embryonic Development
- 5 Motor and Sensory
- 6 CN I Olfactory
- 7 CN II Optic
- 8 CN III Oculomotor
- 9 CN IV Trochlear
- 10 CN V Trigeminal
- 11 CN VI Abducent
- 12 CN VII Facial
- 13 CN VIII Vestibulocochlear
- 14 CN IX Glossopharyngeal
- 15 CN X Vagus
- 16 CN XI Accessory
- 17 CN XII Hypoglossal
- 18 Neonatal - Clinical
- 19 Additional Images
- 20 References
- 21 Glossary Links
|The cranial nerves (ganglia) are represented by a roman numeral (I - XII) and many have additional historic names. They are paired, and can be mixed (motor/sensory), and the brain equivalent of the spinal cord spinal nerves.
In embryonic development, the trigeminal ganglia (CN V, historically the semilunar ganglion, Gasser's ganglion or Gasserian ganglion) is the first to become apparent and is the largest of the cranial nerves.
Neural development is one of the earliest systems to begin and the last to be completed after birth. This development generates the most complex structure within the embryo and the long time period of development means in utero insult during pregnancy may have consequences to development of the nervous system.
Differences between birds and mammals:
Neural development beginnings quite early, therefore also look at notes covering Week 3- neural tube and Week 4-early nervous system. Development of the neural crest and sensory systems (hearing/vision/smell) are only introduced in these notes and are covered in other notes sections.
|CN I||Olfactory||sensory||telencephalon||smell placode|
|CN II||Optic||sensory||retinal ganglial cells||vision|
|CN III||Oculomotor||motor||anterior midbrain||extraocular muscles eye movements and pupil dilation (motor)|
|CN IV||Trochlear||motor||dorsal midbrain||extraocular muscles (superior oblique muscle)|
|CN V||Trigeminal||motor/sensory||pons||touch, mastication|
|CN VI||Abducent||motor||extraocular muscles||control eye movements (lateral rectus muscle)|
|CN VII||Facial||motor/sensory||pons||facial expression, taste (tongue anterior and central regions) regulate salivary production.|
|CN VIII||Acoustic||sensory||vestibular and cochlear nuclei||hearing, placode|
|CN IX||Glossopharyngeal||motor/sensory||medulla||swallowing and speech, taste (tongue posterior region)|
|CN X||Vagus||motor/sensory||medulla||larynx and pharynx muscles (speech and swallowing), regulates heartbeat, sweating, and peristalsis|
|CN XI||Accessory||motor||motor neurons||sternocleidomastoid and trapezius muscles|
|CN XII||Hypoglossal||motor||motor neurons||tongue muscles (speech, eating and other oral functions)|
|Cranial Nerve Links: Neural | Neural Crest | CN I | CN II | CN III| CN IV | CN V | CN VI | CN VII | CN VIII | CN IX | CN X | CN XI | CN XII | placodes | Category:Cranial Nerve|
Some Recent Findings
|More recent papers|
This table allows an automated computer search of the external PubMed database using the listed "Search term" text link.
Search term: Cranial Nerve Development
|These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table.|
Neural Development Overview
Neuralation begins at the trilaminar embryo with formation of the notochord within the mesoderm that underlies the ectoderm and do not physically contribute to the nervous system, but is involved with patterning its initial formation. The central portion of the ectoderm then forms the neural plate that folds to form the neural tube, that will eventually form the entire central nervous system.
- Early developmental sequence: Epiblast - Ectoderm - Neural Plate - Neural groove and Neural Crest - Neural Tube and Neural Crest
|Neural Tube||Primary Vesicles||Secondary Vesicles||Adult Structures|
|week 3||week 4||week 5||adult|
|prosencephalon (forebrain)||telencephalon||Rhinencephalon, Amygdala, hippocampus, cerebrum (cortex), hypothalamus, pituitary | Basal Ganglia, lateral ventricles|
|diencephalon||epithalamus, thalamus, Subthalamus, pineal, posterior commissure, pretectum, third ventricle|
|mesencephalon (midbrain)||mesencephalon||tectum, Cerebral peduncle, cerebral aqueduct, pons|
|myelencephalon||medulla oblongata, isthmus|
|spinal cord, pyramidal decussation, central canal|
|Cranial Nerve Development|
|stage 14||stage 16|
Developed from serially-sectioned human embryos
- An indication of mesencephalic neural crest is discernible already at stage 9, and trigeminal, facial, and postotic components can be detected at stage 10.
- Crest was not observed at the level of diencephalon 2. Although pre-otic crest from the neural folds is at first continuous (stage 10), crest-free zones are soon observable (stage 11) in Rh.1, 3, and 5.
- Emigration of cranial neural crest from the neural folds at the neurosomatic junction begins before closure of the rostral neuropore, and later crest cells do not accumulate above the neural tube.
- The trigeminal, facial, glossopharyngeal and vagal ganglia, which develop from crest that emigrates before the neural folds have fused, continue to receive contributions from the roof plate of the neural tube after fusion of the folds.
- The nasal crest and the terminalis-vomeronasal complex are the last components of the cranial crest to appear (at stage 13) and they persist longer.
- The optic, mesencephalic, isthmic, accessory, and hypoglossal crest do not form ganglia. Cervical ganglion 1 is separated early from the neural crest and is not a Froriep ganglion.
- The cranial ganglia derived from neural crest show a specific relationship to individual neuromeres, and rhombomeres are better landmarks than the otic primordium, which descends during stages 9-14.
- Epipharyngeal placodes of the pharyngeal arches contribute to cranial ganglia, although that of arch 1 is not typical.
- The neural crest from rhombomeres 6 and 7 that migrates to pharyngeal arch 3 and from there rostrad to the truncus arteriosus at stage 12 is identified here, for the first time in the human, as the cardiac crest.
- The hypoglossal crest provides cells that accompany those of myotomes 1-4 and form the hypoglossal cell cord at stages 13 and 14. # The occipital crest, which is related to somites 1-4 in the human, differs from the spinal mainly in that it does not develop ganglia.
- The occipital and spinal portions of the crest migrate dorsoventrad and appear to traverse the sclerotomes before the differentiation into loose and dense zones in the latter.
|Embryonic Central Nervous System|
|Stage 13||Stage 14||Stage 16||Stage 21|
scale bar = 1 mm
|Week 4||Week 5||Week 6||Week 8|
- Human CNS Images: Carnegie stage 13 | Carnegie stage 13 label | Carnegie stage 14 | Carnegie stage 14 label | Carnegie stage 16 | Carnegie stage 16 label | CN V | Carnegie stage 21 lateral | Carnegie stage 21 median | Fetus CRL 240mm | Neural System Development | Cranial Nerves
Motor and Sensory
|Cranial motor nerves brainstem nuclei of origin||Primary Terminal Nuclei of the Afferent (sensory) Cranial Nerves|
During early development each pharyngeal arch is associated with different cranial nerves.
CN I Olfactory
Olfactory Nerve - Human fetus (Week 10)
CN II Optic
Based upon Streeter.
- Carnegie stage 19 - Optic nerve small, slender. Lumen practically whole length of stalk. Few or no fibers.
- Carnegie stage 20 - Ependymal arrangement partially retained along stalk. Remnant of ependyma along whole length of stalk. Hyaloid groove at bulbar end. A few fibers arriving at brain.
- Carnegie stage 21 - Remnant of ependyma present.
- Carnegie stage 22 - Sheath layer beginning to form. Vascular canal present.
- Carnegie stage 23 - Early nerve sheath. Reticular spongioblastic framework, striate arrangement of nuclei, bundles of fibers. Definite nerve sheath.
Optic Nerve - Human embryo (week 8, Carnegie stage 22)
CN III Oculomotor
motor - innervates muscles that enable most eye movement
development - oculomotor nerve is derived from the basal plate of the embryonic midbrain
- Links: vision
|Mann IC. The developing third nerve nucleus in human embryos (1927) J Anat. 61(4): 424-438. PubMed 17104156|
CN IV Trochlear
motor - innervates the superior oblique muscle that enables eye movement
See also the historic 1943 description of this cranial nerve development by Pearson.
- Links: vision
CN V Trigeminal
(semilunar ganglion, Gasser's ganglion or Gasserian ganglion)
This is largest of all the cranial nerves during early development and has three major branches: ophthalmic nerve (V1), maxillary nerve (V2), mandibular nerve (V3)
- sensory - provide tactile, proprioceptive, and nociceptive afference to the face and mouth.
- motor - innervate the skin of the face via ophthalmic (V1), maxillary (V2) and mandibular (V3) divisions. Special visceral efferent (SVE) axons innervate the muscles of mastication via the mandibular (V3) division.
In the embryo, the trigeminal ganglia is first visible in week 4 stage 10, initially developing from neural crest cells before neural fold fusion, and after fusion receive contributions from the neural tube roof plate.
In the adult, cavum trigeminale (Meckel's cave) is an arachnoidal pouch containing cerebrospinal fluid. Though the dura and arachnoid layers end at the trigeminal ganglion and do not extend to cover the three branches of the trigeminal nerve.
Gasser's ganglion or Gasserian ganglion
This historic terminology was given by Antonius Hirsh who described the ganglion in 1765 and then named the ganglion in the honour of his teacher, Johann Lorenz Gasser (1723-1765) an Austrian anatomist.
CN VI Abducent
motor - innervates the lateral rectus muscle that enables eye movement
development - from the basal plate of the embryonic pons
- Links: vision
CN VII Facial
(N. Facialis; Seventh Nerve; CN VII)
Development - second pharyngeal arch
Gray Fig. 788. Plan of the Facial and Intermediate Nerves and their Communication with Other Nerves
|The facial nerve (Figs. 788, 790) consists of a motor and a sensory part, the latter being frequently described under the name of the nervus intermedius (pars intermedii of Wrisberg) (Fig. 788). The two parts emerge at the lower border of the pons in the recess between the olive and the inferior peduncle, the motor part being the more medial, immediately to the lateral side of the sensory part is the acoustic nerve.|
Facial nerve development - right facial nerve and its nucleus of origin (A. 10 mm embryo, C. neonate).
Geniculate ganglion - contains fibres for taste and somatic sensation and is located in the petrous temporal bone.
CN VIII Vestibulocochlear
Cranial nerve eight (CN VIII) In the embryo, cells derive from the otic placode forming the otic vesicle (otocyst). Ganglion previously thought to also involve otic neural crest (rhombomere 4), but recent studies suggest an entirely placodal origin. In the adult, as in its name it consists of 2 parts vestibular (balance and position in space) and cochlear (hearing, spiral).
|Week 5||Week 8|
Embryo Stage 13 showing inner ear and CN VIII.
Embryo Stage 22 showing otocyst and CN VIII.
The historic name for the vestibular ganglion, also called is the ganglion of the vestibular nerve.
CN IX Glossopharyngeal
Mixed motor/sensory and lies anterior to the medulla oblongata
- Branchial motor (special visceral efferent) – supplies the stylopharyngeus muscle.
- Visceral motor (general visceral efferent) – provides parasympathetic innervation of the parotid gland via the otic ganglion.
- Visceral sensory (general visceral afferent) – carries visceral sensory information from the carotid sinus and carotid body.
General sensory (general somatic afferent) – provides general sensory information from inner surface of the tympanic membrane, upper pharynx (GVA), and the posterior one-third of the tongue.
Visceral afferent (special visceral afferent) – provides taste sensation from the posterior one-third of the tongue, including circumvallate papillae.
CN X Vagus
(pneumogastric nerve) responsible for heart rate, gastrointestinal peristalsis, sweating, and muscle movements in the mouth, including speech (via the recurrent laryngeal nerve)
- motor derived from the basal plate of the medulla oblongata
- sensory derived from cranial neural crest
CN XI Accessory
motor - innervates the sternocleidomastoid and trapezius muscles
- sternomastoid - muscle superficial layer side of the neck, rotation of the head
- trapezius - superficial muscles from occipital bone to the lower thoracic vertebrae and laterally to the spine of the scapula, move the scapulae and support the arm.
See also the historic 1938 description of this cranial nerve development by Pearson.
CN XII Hypoglossal
Neonatal - Clinical
Examination of the baby’s cranial nerve function is often accomplished by observing spontaneous activity.
|Newborn - Cranial Nerves|
Mouse E10.5 Nav2 expression
|Historic Disclaimer - information about historic embryology pages|
|Embryology History | Historic Embryology Papers)|
- Kurosaka H, Trainor PA, Leroux-Berger M & Iulianella A. (2015). Cranial nerve development requires co-ordinated Shh and canonical Wnt signaling. PLoS ONE , 10, e0120821. PMID: 25799573 DOI.
- Simon E, Thézé N, Fédou S, Thiébaud P & Faucheux C. (2017). Vestigial-like 3 is a novel Ets1 interacting partner and regulates trigeminal nerve formation and cranial neural crest migration. Biol Open , 6, 1528-1540. PMID: 28870996 DOI.
- Sajgo S, Ali S, Popescu O & Badea TC. (2016). Dynamic expression of transcription factor Brn3b during mouse cranial nerve development. J. Comp. Neurol. , 524, 1033-61. PMID: 26356988 DOI.
- O'Rahilly R & Müller F. (2007). The development of the neural crest in the human. J. Anat. , 211, 335-51. PMID: 17848161 DOI.
- Streeter GL. Developmental Horizons In Human Embryos Description Or Age Groups XIX, XX, XXI, XXII, And XXIII, Being The Fifth Issue Of A Survey Of The Carnegie Collection. (1957) Carnegie Instn. Wash. Publ. 611, Contrib. Embryol., 36: 167-196.
- Pearson AA. The trochlear nerve in human fetuses. (1943) J. Comp. Neurol. : 29-43.
- Kehrli P, Maillot C & Wolff MJ. (1997). Anatomy and embryology of the trigeminal nerve and its branches in the parasellar area. Neurol. Res. , 19, 57-65. PMID: 9090638
- Streeter GL. The nuclei of origin of the cranial nerves in the 10 mm human embryo. (1908) Amer. J Anat. 2:111 - 115.
- McNeill EM, Roos KP, Moechars D & Clagett-Dame M. (2010). Nav2 is necessary for cranial nerve development and blood pressure regulation. Neural Dev , 5, 6. PMID: 20184720 DOI.
- Pearson AA. The spinal accessory nerve in human embryos. (1938) J. Comp. Neurol. 68(2): 243-266.
Barlow LA. (2002). Cranial nerve development: placodal neurons ride the crest. Curr. Biol. , 12, R171-3. PMID: 11882306
Saitsu H & Shiota K. (2008). Involvement of the axially condensed tail bud mesenchyme in normal and abnormal human posterior neural tube development. Congenit Anom (Kyoto) , 48, 1-6. PMID: 18230116 DOI.
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Cite this page: Hill, M.A. (2020, May 31) Embryology Neural - Cranial Nerve Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Neural_-_Cranial_Nerve_Development
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