• The Korean Journal of Physiology
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• v.11 no.2
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• pp.51-56
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• 1977

In Nembutal anesthetized cats, the sobmaxillary duct was cannulated with polyethylene tube, and effects of stimulation of the chorda tympani and cervical sympathetics on, the submaxillary secretion and intraluminal pressure of the submaxillary duct were observed. The stimulation of tile chorda tympani elicited a profuse salivary secretion. The stimulation of the cervical sympathetics evoked only a scanty flow, and on repeated stimulation of the nerve salivary flow response gradually diminished and finally the flow ceased. In this state the salivary flow by the sympathetic stimulation was resumed after the stimulation of the chorda tympani. Atropine abolished these responses to nerve stimulation. Intraluminal pressure of the submaxillary duct was abruptly increased and remained on a plateau during the stimulation of the chorda tympani, whereas sympathetic stimulation elicited moderate increase of the intraluminal pressure which did not remain in spite of continued stimulation. These results suggest that scanty salivary flow induced by cervical sympathetic stimulation is not real secretion but simple elimination of the saliva already present in the duct due to contraction of the contractile elements known to exist in the duct wall.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.37-43
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• 1991

The nerve impulse pattern of Chorda tympani(CT) of cat was tested with Monosodium glutamate(MSG) solutions as well as some basic taste substances applied on the tongue of cat. The effect of MSG applied in the tongue prior to the stimulation of other taste substances was also investigated. The response impulse frequency of CT of cat was changed by the kind and concentration of taste substances. The response to citric acid was the highest among the tested substances, NaCl, KCl and MSG showed similar responses. When different concentrations of MSG were applied on the tongue prior to other substances, the response to NaCl increased with the maximum response at the MSG concentration of 0.02 M. The response to sucrose tended to be reduced, but the response to citric acid was distinctly supressed by the previous MSG stimulation. These results were well consistent with the sensory evaluation on the effect of MSG to some basic taste substances. previously reported by the authors.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.313-321
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• 1987

To investigate whether the cervical sympathetics contains specific secretory fibers for the salivary glands, reflex salivation was evoked and the role of the sympathetics or the reflex was examined in ketamine-anesthetized cat. Stimulation of the central end of the glossopharyngeal nerve produced a copious secretion from the submaxillary gland and the response was not affected by the section of the cervical sympathetics or by the administration of phenoxybenzamine, whereas the response was abolished by severing the chorda tympani or by the administration of atropine. The salivary response was always associated with an increase in glandular blood flow. Both salivary and blood flow responses were decreased markedly by the superimposed stimulation of the cervical sympathetics or by the administration of norepinephrine. The decreased submaxillary blood flow always preceded the decrease in salivary flow on stimulation of the cervical sympathetics and the decreased blood flow recovered prior to the salivary flow upon cessation of the sympathetic stimulation. The inhibitory effects of the sympathetics and norepinephrine were completely abolished by the pretreatment with phenoxybenzamine. These results indicate that the glossopharyngeal nerve is one of the afferent limbs of the submaxillary salivary reflex and the chorda tympani is the only efferent limb of the reflex pathway. Thus, it is suggested that the cervical sympathetics does not contain the specific secretory fibers for the gland, but plays a role in inhibiting the reflex secretion by decreasing the blood flow to the gland.

• Journal of Oral Medicine and Pain
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• v.33 no.4
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• pp.295-303
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• 2008

The lingual branch of the trigeminal nerve transmitts general sensation from anterior two thirds of the tongue, also bearing within sheath fibers of chordal tympani branch of the facial nerve. Chorda tympani nerve carries special taste sensations from the anterior two thirds of the tongue and sub-serves the existing trigeminal pathway. Chorda tympani nerve and the lingual nerve innervate to fungiform papilla and distribution of fungiform papilla on tongue dorsum is variable according to anatomical location. The purpose of this report is to assess that the relationship of the number of fungiform papilla and the ability of two-point discrimination of tongu dorsum. Twenty-six healthy students(male:female=13:13) whose mean age was $30{\pm}3$ participated in our study. Two-point discrimination thresholds were measured to evaluate the spatial acuity of touch sensation. The measurement was carried out at the tip and posterolateral region of dorsal tongue. After two-point discrimination test, we took the pictures of their dorsal tongue dyed with methylene blue with digital camera. There were no significant differences between the number of fungiform papilla and the two-point discrimination threshold. But, we found that there were the intraregional and intersubject variations of spatial acuity of the tongue. During the test on the posterolateral region of the dorsal tongue, students appealed the difficulty of discrimination of one point and two point.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.2
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• pp.118-128
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• 2001

Two major salivary glands, submandibular duct, lingual nerve, and vessels are situated beneath the mouth floor. Among these, passing through the pterygomandibular space, lingual nerve is innervated to the lingual gingiva and the mucosa of mouth floor, and is responsible for the general sensation of the anterior two thirds of the tongue. So, the injury of the lingual nerve during an anesthesia or surgery in the retromolar area may cause complications such as a numbness, a loss of taste of the tongue and the other dysfunctions. Therefore, to find out the morphology and the course of lingual nerve and to clarify the topographical relationships of lingual nerve at the infratemporal fossa and paralingual space area, 32 Korean hemi-sectioned heads were dissected macroscopically and microscopically with a viewpoint of clinical aspect in this study. This study demonstrated various anatomical characteristics with relation to the course and topography of the lingual nerve in Koreans. And clinical significances based on the anatomical variations through the topography of the courses and communications between the mandibular nerve branches were described in details.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.6
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• pp.437-443
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• 2011

Salt signals in tongue are relayed to the nucleus of the solitary tract (NST). This signaling is very important to determine whether to swallow salt-related nutrition or not and suggests some implications in discrimination of salt concentration. Salt concentration-dependent electrical responses in the chorda tympani and the NST were well reported. But salt concentration-dependency and spatial distribution of c-Fos in the NST were not well established. In the present study, NaCl signaling in the NST was studied in urethane-anesthetized rats. The c-Fos immunoreactivity in the six different NST areas along the rostral-caudal axis and six subregions in each of bilateral NST were compared between applications of distilled water and different concentrations of NaCl to the tongue of experimental animals. From this study, salt stimulation with high concentration (1.0 M NaCl) induced significantly higher c-Fos expression in intermediate NST and dorsal-medial and dorsal-middle subregions of the NST compared to distilled water stimulation. The result represents the specific spatial distribution of salt taste perception in the NST.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.17-25
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• 1997

The evoked potentials for concentrations of solutions of the four qualities of tastes(i.e., sweet, salty, sour, and bitter tastes) were measured. The solution was applied to the chorda tympani nerve located on the left side of the tongue at 20mm from the tip and 15mm left from the center line. The evoked potentials were detected from Cz referred to A1(left lobe) with the ground at the Fpz position. The Maximum potential level and its latency were evaluated. The individual threshold level of concentration of the solutions of four tastes were measured. Artificial saliva was used as a control solution. The evoked positive potentials for four qualities of tastes (i.e., gustatory evokde potentials) were found to be around 150ms by averaging eight responses. The arbitrary concentration of the solutions were presented by the relative concentration, which was the ratio of the arbitrary concentration to the individual threshold level. The characteristic relations between the latency and the relative concentration ;and those between the potential level and the relative concentration were evaluated. These evalutions showed that (1) the latencies for salty and bitter tastes denoted the minimum values due to for the change of relative concentration, and that (2) the latency for sour taste decreased as the relative concentrations increased, while the latency for sweet taste denoted the inverse tendency, Sinificant differences between any two maximum potential levels were not recognized. A response latencies to sucrose were abolished after treatment of tongue by a sweet-suppressing agent.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1982.05a
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• pp.17.2-19
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• 1982

The sinus tympani is subject to great variability in the size, shape and posterior extent. A heavy compact bony zone, especially in the posterior portion and the narrow space between the facial nerve and posterior semicircular canal are the limitation of surgical approach. The facial recess should be opened, creating a wide connection between the mesotympanum and mastoid in the Intact canal wall tympanoplasty with mastoidectomy. The surgically created limits of the facial recess are the facial nerve medially, the chorda tympani laterally and the bone adjacent to the incus superiorly. Using adult Korean's thirty-five temporal bones, the authors measured the osteologic reslationship in the posterior tympanum, especially sinus tympani and facial recess. The result was as followed. 1. The average distance from the anterior end of the pyramidal eminence. 1) to the edge of the sinus tympani directly posterior was 2.54(1.05-5.40)mm. 2) to the maximum posterior extent was 3.22(1.25-7.45)mm. 3) to the maximum cephaled extent was 0.67 (0.40-1.75)mm. 2. The boundary of the sinus tympani was 82.9% from the lower margin oval window to the upper margin round window niche. 3. The deepest part of the sinus tympani was 62.9% in the mid portion, between the ponticulus and subiculum. 4. The oblique dimension from the fossa incudis above to the hypotympanum below was 8.13(7.90-9.55)mm. 5. The transverse dimensions midway between the oval window above and round window below was 3.00(2.85-3.45)mm. 6. The transverse dimension at the level of the fossa incudis was 1.81(1.40-2.15)mm. 7. The facial nerve dehiscence was 14.3%. 8. Anterior-posterior diameter of the footplate was 2.98(2.85-3.05) mm. 9. The average distance from the footplate. 1) to the cochleariform process was 1.42(1.35-1.55) mm. 2) to the round window niche was 1.85(1.45-2.10) mm.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.1-9
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• 1986

This study was carried out to investigate the branch and distribution of Nervus facialis of the Korean native goat. The observation was made by dissection of embalmed cadavers of ten Korean native goats. The results were as follows; 1. N. facialis arose from the ventrolateral surface of the medulla oblongata. 2. In the facial canal, N. facialis gave off N. petrosus major, N. stapedius and Chorda tympani. 1) N. petrosus major arose from Ganglion geniculi, passed through the pterygoid canal and terminated in Ganglion pterygopalatinum. 2) Chorda tympani joined N. lingualis at the lateral surface of the internal pterygoid muscle. 3. At the exit of the stylomastoid foramen, N. facialis gave off N. caudalis auricularis, Ramus auricularis internus, Ramus stylohyoideus and Ramus digastricus. 1) N. caudalis auricularis arose by two branches in 6 cases and by a single branch in 4 cases. N. caudalis auricularis gave off branches to the caudoauricuIar muscles and the internal surface of the conchal cavity. 2) Ramus auricularis internus arose by a single branch except in 2 cases in which it arose in common with N. caudalis auricularis. It penetrated the caudolateral surface of the tragus and distributed in the skin of the scapha. 3) Ramus stylohyoideus and Ramus digastricus arose separately from N. facialis. 4. In the deep surface of the parotid gland, N. facialis divided into N. auriculopalpebralis, Ramus buccalis dorsalis and Ramus buccalis ventralis. In 6 cases, N. facialis gave off Ramus buccalis ventralis and then divided into N. auriculopalpebralis and Ramus buccalis dorsalis. In 3 cases, N. facialis trifurcated into Ramus buccalis ventralis, Ramus buccalis dorsalis and N. auriculopalpebralis. In one case, N. facialis gave off N. auriculopalpebralis and then divided into Ramus buccalis dorsalis and Ramus buccalis ventralis. 1) Ramus buccalis ventralis ran along the ventral border of the masseter muscle and distributed to the buccinator and depressor labii inferioris muscles. Ramus buccalis ventralis communicated with a branch of Ramus buccalis dorsalis and N. buccalis. In 2 cases, it also communicated with N. mylohyoideus. 2) Ramus buccalis dorsalis communicated with Ramus transverses faciei, N. buccalis, N. infraorbitalis and a branch of Ramus buccalis ventralis. Ramus buccalis dorsalis distributed to the orbicularis oris, caninus, depressor labii inferioris, levator labii superioris, buccinator, malaris, nasolabialis and zygomaticus muscles. 3) N. auriculopalpebralis gave off Rami auriculares rostrales, which supplied the zygomaticoauricularis muscle, the frontoscutularis muscle and the skin of the base of the ear. N. auriculopalpebralis then continued as Ramus zygomaticus, which innervated the frontal muscle, the lateral surface of the base of the horn, the orbicularis oculi muscle and the adjacent skin of the orbit. N. auriculopalpebralis communicated with Nn. auriculares rostrales and Ramus zygomaticotemporalis. In 7 cases, it also communicated with N. infratrochlearis.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.87-99
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• 1991

In order to elucidate whether capsaicin applied topically acts as a pain-producing subastance or as a tastant, neuronal activities of the chorda tympani nerve(CN), lingual nerve(LN), solitary tract nucleus(STN), and trigeminal nucleus(TGN) were recorded while thermal and taste stimuli, and capsaicin were being applied topically, and algesics intra-arterially to the tongue of cats anesthetized with ${\alpha}-chloralsoe$. In addition, the STN neurons were examined after wheat germ agglutinin-horseradish peroxidase(WGA-HRP) was applied to the CN. The CN fibers responded to taste and thermal stimuli, algesics, and capsaicin. Responses to capsaicin were significantly correlated with those to taste and thermal stimuli. The LN fibers mainly responded to mechanical and thermal stimuli, algesics, and capsaicin. Responses to capsaicin were significantly correlated with those to algesics. The STN neurons responded to taste and thermal stiumli, algesics, and capsaicin. Responses to capsaicin were significantly correlated with those to taste and thermal stiumli in somewhat different fashion from those of the CN fibers. The TGN neurons mainly responded to mechanical stimuli, algesics, and capsaicin. Correlations between responses to capsaicin and any others were not significant. After WGA-HRP was applied to the CN, the STN neurons which receive input from the CN were identified largely in the medio-ventral portion to the solitary tract. These results suggest that capsaicin produce taste as well as pain sensation. Sensory information evoked by capsaicin can be conveyed to the STN, especially medio-ventral portion, via the CN as gustatory information on the one hand, and to the STN or TGN via the LN as noxious information on the other. In addiation, the noxious information may be conveyed to the STN via the CN.