WordNet

any bundle of nerve fibers running to various organs and tissues of the body (同)nervus
play chords on (a string instrument)
a straight line connecting two points on a curve
a combination of three or more notes that blend harmoniously when sounded together
control of your emotions; "this kind of tension is not good for my nerves"

PrepTutorEJDIC

〈C〉『神経』 / 〈C〉《複数形で》『神経過敏』,いらだち / 〈U〉『勇気』,度胸(courage) / 〈U〉《時にa ~》厚かましさ,ずぶとさ;無礼 / 〈C〉葉脈;(昆虫の)翅脈(しみゃく) / 〈人,特に自分〉‘に'力を与える,‘を'元気づける
(楽器の)弦 / 感情,情緒 / 和音,コード / =cord4 / 弦(数学で,円周上の2点を結ぶ直線)
=timpani

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/02/05 21:40:56」(JST)

wiki en

The chorda tympani is a branch of the facial nerve that originates from the taste buds in the front of the tongue, runs through the middle ear, and carries taste messages to the brain. It joins the facial nerve (cranial nerve VII) inside the facial canal, at the level where the facial nerve exits the skull via the petrotympanic fissure.^[1]

The chorda tympani is part of one of three cranial nerves that are involved in taste. The taste system involves a complicated feedback loop, with each nerve acting to inhibit the signals of other nerves. The chorda tympani appears to exert a particularly strong inhibitory influence on other taste nerves, as well as on pain fibers in the tongue. When the chorda tympani is damaged, its inhibitory function is disrupted, leading to less inhibited activity in the other nerves.^{[citation needed]}

Structure

The chorda tympani exits the cranial cavity through the internal acoustic meatus along with the facial nerve, then it travels through the middle ear, where it runs from posterior to anterior across the tympanic membrane. It passes between the malleus and the incus, on the medial surface of the neck of the malleus.

The nerve continues through the petrotympanic fissure, after which it emerges from the skull into the infratemporal fossa. It soon joins the pathway of the larger lingual nerve, a branch of the mandibular nerve.

The fibers of the chorda tympani travel with the lingual nerve to the submandibular ganglion.

Here, the preganglionic fibers of the chorda tympani synapse with postganglionic fibers which go on to innervate the submandibular and sublingual salivary glands.

Special sensory (taste) fibers also extend from the chorda tympani to the anterior 2/3 of the tongue via the lingual nerve.

Function

The chorda tympani carries two types of nerve fibers from their origin with the facial nerve to the lingual nerve that carries them to their destinations:

Special sensory fibers providing taste sensation from the anterior two-thirds of the tongue.^{[citation needed]}
Presynaptic parasympathetic fibers to the submandibular ganglion, providing secretomotor innervation to two salivary glands: the submandibular gland and sublingual gland and to the vessels of the tongue, which when stimulated, cause a dilation of blood vessels of the tongue.^{[citation needed]}

Right chorda tympani nerve, viewed from lateral side

Taste

There are similarities between the tastes the chorda tympani picks up in sweeteners between mice and primates, but not rats. Relating research results to humans is therefore not always consistent.^[2] Sodium chloride is detected and recognized most by the chorda tympani nerve.^[2] The recognition and responses to sodium chloride in the chorda tympani is mediated by amiloride-sensitive sodium channels.^[3] The chorda tympani has a relatively low response to quinine and varied responses to hydrochloride. The chorda tympani is less responsive to sucrose than is the greater superficial petrosal nerve.^[4]

Chorda tympani transection

The chorda tympani nerve carries its information to the nucleus of the solitary tract, and shares this area with the greater superficial petrosal and glossopharyngeal nerves. When the greater superficial petrosal and glossopharyngeal nerves are cut, regardless of age, the chorda tympani nerve takes over the space in the terminal field. This takeover of space by the chorda tympani is believed to be the nerve reverting to its original state before competition and pruning.^[5] The chorda tympani, as part of the peripheral nervous system, is not as plastic in early ages. In a study done by Hosley et al. and a study done by Sollars, it has been shown that when the nerve is cut at a young age, the related taste buds are not likely to grow back to full strength.^[6]^[7] In a bilateral transection of the chorda tympani in mice, the preference for sodium chloride increases compared to before the transection. Also avoidance of higher concentrations of sodium chloride is eliminated.^[2] The amiloride-sensitive channels responsible for salt recognition and response is functional in adult rats but not neonatal rats. This explains part of the change in preference of sodium chloride after a chorda tympani transection.^[3] The chorda tympani innervates the fungiform papillae on the tongue.^[7] According to a study done by Sollars et al. in 2002, when the chorda tympani has been transected early in postnatal development some of the fungiform papillae undergo a structural change to become more “filliform-like”.^[8] When some of the other papillae grow back, they do so without a pore.^[7]

Additional images

Mandible of human embryo 24 mm. long. Outer aspect.
Distribution of the maxillary and mandibular nerves, and the submaxillary ganglion.
Plan of the facial and intermediate nerves and their communication with other nerves.
The course and connections of the facial nerve in the temporal bone.
Sympathetic connections of the submaxillary and superior cervical ganglia.
View of the inner wall of the tympanum (enlarged.)
Dissection of chorda tympani nerve
Lateral head anatomy detail.Facial nerve dissection.

References

^ Kwong, Y; Yu, D; Shah, J (August 2012). "Fracture mimics on temporal bone CT: a guide for the radiologist.". AJR. American journal of roentgenology 199 (2): 428–34. doi:10.2214/ajr.11.8012. PMID 22826408.
^ ^a ^b ^c Golden, G. J.; Ishiwatari, Y.; Theodorides, M. L.; Bachmanov, A. A. (2011). "Effect of Chorda Tympani Nerve Transection on Salt Taste Perception in Mice". Chemical Senses 36 (9): 811–9. doi:10.1093/chemse/bjr056. PMC 3195788. PMID 21743094.
^ ^a ^b Sollars, Suzanne I.; Bernstein, Ilene L. (1994). "Amiloride sensitivity in the neonatal rat". Behavioral Neuroscience 108 (5): 981–7. doi:10.1037/0735-7044.108.5.981. PMID 7826520.
^ Sollars, Suzanne I.; Hill, David L. (2005). "In vivorecordings from rat geniculate ganglia: Taste response properties of individual greater superficial petrosal and chorda tympani neurones". The Journal of Physiology 564 (3): 877–93. doi:10.1113/jphysiol.2005.083741. PMC 1464453. PMID 15746166.
^ Corson, S. L.; Hill, D. L. (2011). "Chorda Tympani Nerve Terminal Field Maturation and Maintenance is Severely Altered Following Changes to Gustatory Nerve Input to the Nucleus of the Solitary Tract". Journal of Neuroscience 31 (21): 7591–603. doi:10.1523/JNEUROSCI.0151-11.2011. PMC 3117282. PMID 21613473.
^ Hosley, M. A.; Hughes, S. E.; Morton, L. L.; Oakley, B (1987). "A sensitive period for the neural induction of taste buds". The Journal of Neuroscience 7 (7): 2075–80. PMID 3612229.
^ ^a ^b ^c Sollars, Suzanne I. (2005). "Chorda tympani nerve transection at different developmental ages produces differential effects on taste bud volume and papillae morphology in the rat". Journal of Neurobiology 64 (3): 310–20. doi:10.1002/neu.20140. PMID 15898061.
^ Sollars, Suzanne I.; Smith, Peter C.; Hill, David L. (2002). "Time course of morphological alterations of fungiform papillae and taste buds following chorda tympani transection in neonatal rats". Journal of Neurobiology 51 (3): 223–36. doi:10.1002/neu.10055. PMID 11984844.

External links

Anatomy figure: 27:03-08 at Human Anatomy Online, SUNY Downstate Medical Center
Cranial Nerves at Yale 7-18

MedEd at Loyola GrossAnatomy/h_n/cn/cn1/cnb7c.htm
cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (VII)
Photo at Washington University

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. ベル麻痺：成人における病因、臨床的特徴、および診断 bells palsy pathogenesis clinical features and diagnosis in adults
2. 小児における顔面神経麻痺 facial nerve palsy in children
3. 成人における第三脳神経（動眼神経）麻痺 third cranial nerve oculomotor nerve palsy in adults
4. 神経伝導検査の概要 overview of nerve conduction studies
5. 下肢末梢神経症候群の概要 overview of lower extremity peripheral nerve syndromes

English Journal

Anxiolytic efficacy of repeated oral capsaicin in rats with partial aberration of oral sensory relay to brain.

Choi YJ1, Kim JY2, Jin WP2, Kim YT3, Lee JH4, Jahng JW5.
Archives of oral biology.Arch Oral Biol.2015 Jul;60(7):989-97. doi: 10.1016/j.archoralbio.2015.01.018. Epub 2015 Mar 28.
OBJECTIVE: This study was conducted to examine if taste over load with oral capsaicin improves the adverse behavioural effects induced by partial aberration of oral sensory relays to brain with bilateral transections of the lingual and chorda tympani nerves.DESIGN: Male Sprague-Dawley rats received
PMID 25874812

CALHM1 Deletion in Mice Affects Glossopharyngeal Taste Responses, Food Intake, Body Weight, and Life Span.

Hellekant G1, Schmolling J2, Marambaud P3, Rose-Hellekant TA2.
Chemical senses.Chem Senses.2015 Jul;40(6):373-9. doi: 10.1093/chemse/bjv009. Epub 2015 Apr 8.
Stimulation of Type II taste receptor cells (TRCs) with T1R taste receptors causes sweet or umami taste, whereas T2Rs elicit bitter taste. Type II TRCs contain the calcium channel, calcium homeostasis modulator protein 1 (CALHM1), which releases adenosine triphosphate (ATP) transmitter to taste fibe
PMID 25855639

The feasibility of endoscopic transcanal approach for insertion of various cochlear electrodes: a pilot study.

Migirov L1, Shapira Y, Wolf M.
European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery.Eur Arch Otorhinolaryngol.2015 Jul;272(7):1637-41. doi: 10.1007/s00405-014-2995-5. Epub 2014 Mar 12.
To determine the feasibility of inserting various types of electrode arrays using an endoscopic transcanal approach into the cochlea via the round window membrane (RWM). All the procedures were performed by the first author and started with a cortical mastoidectomy. A six o'clock vertical incision w
PMID 24619204

Japanese Journal

P-038 鼓索神経・嗅球への電気刺激に対する一次味覚野および周辺領域における応答変化(ポスターセッション,2015年度日本味と匂学会第49回大会)

日本味と匂学会誌 22(3), 279-282, 2015-12
NAID 110010041341

老化に伴うラットの味覚嗜好性の変化

鹿児島大学歯学部紀要 35, 11-19, 2015-03-25
NAID 120005758076

A Case of Schwannoma of the Chorda Tympani with Facial Palsy

耳鼻咽喉科臨床　補冊 144(0), 16-17, 2015
NAID 130005110231

Related Pictures

★リンクテーブル★

リンク元	「鼓索神経」
関連記事	「nerve」「chorda」「tympani」

「鼓索神経」

Chorda tympani
	The right membrana tympani with the hammer and the chorda tympani, viewed from within, from behind, and from above.
Details
From	facial nerve
Identifiers
MeSH	A08.800.800.120.250.120
Dorlands; /Elsevier	c_31/12236891
TA	A14.2.01.084; A14.2.01.118
FMA	53228
	Anatomical terms of neuroanatomy [edit on Wikidata]