“Electric Taste” after Section of the Chorda Tympani

Nature ◽  
1967 ◽  
Vol 214 (5093) ◽  
pp. 1113-1114 ◽  
Author(s):  
N. ROBBINS
Keyword(s):  
Chorda Tympani ◽  
Electric Taste

scholarly journals Neurophysiological and biophysical evidence on the mechanism of electric taste.

1985 ◽  
Vol 86 (1) ◽  
pp. 59-87 ◽  
Author(s):  
M S Herness
Keyword(s):  
Iodoacetic Acid ◽  
Transport Numbers ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Lingual Epithelium ◽  
Ion Migration ◽  
Before And After ◽  
Accumulation Mechanism ◽  
Current Densities ◽  
Electric Taste

The phenomenon of electric taste was investigated by recording from the chorda tympani nerve of the rat in response to both electrical and chemical stimulations of the tongue with electrolytes in order to gain some insight into its mechanism on both a neurophysiological and biophysical basis. The maximum neural response levels were identical for an individual salt (LiCl, NaCl, KCl, or CaCl2), whether it was presented as a chemical solution or as an anodal stimulus through a subthreshold solution. These observations support the idea that stimulation occurs by iontophoresis of ions to the receptors at these current densities (less than 100 microA/cm2). Electric responses through dilute HCl were smaller than the chemically applied stimulations, but the integrated anodal responses appeared similar to chemical acid responses, as evidenced by an OFF response to both forms of stimuli. Hydrogen may be more permeant to the lingual epithelium and would thus be shunted away from the taste receptors during anodal stimulation. When the anion of electric taste was varied via subthreshold salt solutions, the response magnitude increased as the mobility of the anion decreased. The transport numbers of the salts involved adequately explains these differences. The physical aspects of ion migration occurring within the adapting fluid on the tongue are also discussed. Direct neural stimulation by the current appears to occur only at higher current densities (greater than 300 microA/cm2). If the taste cells of the tongue were inactivated with either iodoacetic acid (IAA) or N-ethyl maleimide (NEM), or removed with collagenase, then responses from the chorda tympani could be obtained only at these higher current densities. Latency measurements before and after IAA or NEM treatment corroborated these findings. The results are discussed in terms of several proposed mechanisms of electric taste and it is concluded that an ion accumulation mechanism can adequately explain the data.

scholarly journals Cell non-autonomous requirement of p75 in the development of geniculate oral sensory neurons

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tao Tang ◽  
Christopher R. Donnelly ◽  
Amol A. Shah ◽  
Robert M. Bradley ◽  
Charlotte M. Mistretta ◽  
...  
Keyword(s):  
Sensory Neurons ◽  
Significant Loss ◽  
Taste Buds ◽  
Neurotrophin Receptor ◽  
P75 Neurotrophin Receptor ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Tactile Stimuli ◽  
Oral Sensory ◽  
Nerve Recordings

AbstractDuring development of the peripheral taste system, oral sensory neurons of the geniculate ganglion project via the chorda tympani nerve to innervate taste buds in fungiform papillae. Germline deletion of the p75 neurotrophin receptor causes dramatic axon guidance and branching deficits, leading to a loss of geniculate neurons. To determine whether the developmental functions of p75 in geniculate neurons are cell autonomous, we deleted p75 specifically in Phox2b + oral sensory neurons (Phox2b-Cre; p75fx/fx) or in neural crest-derived cells (P0-Cre; p75fx/fx) and examined geniculate neuron development. In germline p75−/− mice half of all geniculate neurons were lost. The proportion of Phox2b + neurons, as compared to Phox2b-pinna-projecting neurons, was not altered, indicating that both populations were affected similarly. Chorda tympani nerve recordings demonstrated that p75−/− mice exhibit profound deficits in responses to taste and tactile stimuli. In contrast to p75−/− mice, there was no loss of geniculate neurons in either Phox2b-Cre; p75fx/fx or P0-Cre; p75fx/fx mice. Electrophysiological analyses demonstrated that Phox2b-Cre; p75fx/fx mice had normal taste and oral tactile responses. There was a modest but significant loss of fungiform taste buds in Phox2b-Cre; p75fx/fx mice, although there was not a loss of chemosensory innervation of the remaining fungiform taste buds. Overall, these data suggest that the developmental functions of p75 are largely cell non-autonomous and require p75 expression in other cell types of the chorda tympani circuit.

scholarly journals Postoperative radiological assessment of the mastoid facial canal in cochlear implant patients in correlation with facial nerve stimulation

2021 ◽  
Author(s):  
Iris Burck ◽  
Rania A. Helal ◽  
Nagy N. N. Naguib ◽  
Nour-Eldin A. Nour-Eldin ◽  
Jan-Erik Scholtz ◽  
...  
Keyword(s):  
Facial Nerve ◽  
Cochlear Implant ◽  
Nerve Stimulation ◽  
Lateral Wall ◽  
Facial Canal ◽  
Chorda Tympani ◽  
Radiological Assessment ◽  
Canal Diameter ◽  
History Of ◽  
Facial Nerve Stimulation

Abstract Objectives To correlate the radiological assessment of the mastoid facial canal in postoperative cochlear implant (CI) cone-beam CT (CBCT) and other possible contributing clinical or implant-related factors with postoperative facial nerve stimulation (FNS) occurrence. Methods Two experienced radiologists evaluated retrospectively 215 postoperative post-CI CBCT examinations. The mastoid facial canal diameter, wall thickness, distance between the electrode cable and mastoid facial canal, and facial-chorda tympani angle were assessed. Additionally, the intracochlear position and the insertion angle and depth of electrodes were evaluated. Clinical data were analyzed for postoperative FNS within 1.5-year follow-up, CI type, onset, and causes for hearing loss such as otosclerosis, meningitis, and history of previous ear surgeries. Postoperative FNS was correlated with the measurements and clinical data using logistic regression. Results Within the study population (mean age: 56 ± 18 years), ten patients presented with FNS. The correlations between FNS and facial canal diameter (p = 0.09), wall thickness (p = 0.27), distance to CI cable (p = 0.44), and angle with chorda tympani (p = 0.75) were statistically non-significant. There were statistical significances for previous history of meningitis/encephalitis (p = 0.001), extracochlear-electrode-contacts (p = 0.002), scala-vestibuli position (p = 0.02), younger patients’ age (p = 0.03), lateral-wall-electrode type (p = 0.04), and early/childhood onset hearing loss (p = 0.04). Histories of meningitis/encephalitis and extracochlear-electrode-contacts were included in the first two steps of the multivariate logistic regression. Conclusion The mastoid-facial canal radiological assessment and the positional relationship with the CI electrode provide no predictor of postoperative FNS. Histories of meningitis/encephalitis and extracochlear-electrode-contacts are important risk factors. Key Points • Post-operative radiological assessment of the mastoid facial canal and the positional relationship with the CI electrode provide no predictor of post-cochlear implant facial nerve stimulation. • Radiological detection of extracochlear electrode contacts and the previous clinical history of meningitis/encephalitis are two important risk factors for postoperative facial nerve stimulation in cochlear implant patients. • The presence of scala vestibuli electrode insertion as well as the lateral wall electrode type, the younger patient’s age, and early onset of SNHL can play important role in the prediction of post-cochlear implant facial nerve stimulation.

Rate of Recovery of Taste Function after Preservation of Chorda Tympani Nerve in Middle Ear Surgery with Special Reference to Type of Disease

2003 ◽  
Vol 112 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Masafumi Sakagami ◽  
Mieko Sone ◽  
Keijiro Fukazawa ◽  
Kojiro Tsuji ◽  
Yasuo Mishiro
Keyword(s):  
Recovery Of Function ◽  
Inflammatory Diseases ◽  
Chronic Otitis Media ◽  
Normal Function ◽  
Middle Ear Surgery ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Taste Disturbance ◽  
Postoperative Symptoms ◽  
Rate Of Recovery

To study the recovery of function of the chorda tympani nerve, we examined by electrogustometry 79 patients (83 ears) with both preoperative normal function of the nerve and operative preservation of the nerve, every 2 days during hospitalization and at 6 months after surgery. For symptoms such as tongue numbness and taste disturbance, patients with noninflammmatory (NI) diseases (13/20 or 65.0%) showed a significantly higher rate of symptoms than did patients with chronic otitis media (COM; 13/35 or 37.1%) at 2 weeks after surgery (p = .032). The patients with NI diseases (5/20 or 25.0%) tended to show a higher rate of symptoms than did the COM patients (2/35 or 5.7%) or cholesteatoma patients (2/28 or 7.1%) at 6 months after surgery. The rate of recovery of the EGM threshold to normal at 2 weeks after surgery was significantly lower in NI disease patients (6/20 or 30.0%) than in COM patients (23/ 35 or 62.9%) or cholesteatoma patients (19/28 or 67.9%; p = .015 and .008, respectively). Thus, the patients with NI diseases had postoperative symptoms and elevation of EGM threshold more frequently than did the patients with inflammatory diseases.

Loss of sensitivity to low concentrations of NaCl following bilateral chorda tympani nerve sections in rats

1994 ◽  
Vol 19 (2) ◽  
pp. 169-184 ◽  
Author(s):  
Gwen B. O'Keefe ◽  
Juliann Schumm ◽  
James C. Smith
Keyword(s):  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Low Concentrations

Chorda tympani nerve, may it have a role in stabilizing middle ear pressure?

2013 ◽  
Vol 80 (6) ◽  
pp. 726-727 ◽  
Author(s):  
V. Rinaldi ◽  
M. Cappadona ◽  
M. Gaffuri ◽  
S. Torretta ◽  
L. Pignataro
Keyword(s):  
Middle Ear ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Middle Ear Pressure

Behavioral and Single Chorda Tympani Taste Fiber Responses in the Common Marmoset,: Callithrix jacchus jacchus

1998 ◽  
Vol 855 (1 OLFACTION AND) ◽  
pp. 160-164 ◽  
Author(s):  
VICKTORIA DANILOVA ◽  
GORAN HELLEKANT ◽  
THOMAS ROBERTS ◽  
JEAN-MARIE TINTI ◽  
CLAUDE NOFRE
Keyword(s):  
Common Marmoset ◽  
Callithrix Jacchus ◽  
Chorda Tympani ◽  
The Common ◽  
Callithrix Jacchus Jacchus
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