scholarly journals In vivorecordings from rat geniculate ganglia: taste response properties of individual greater superficial petrosal and chorda tympani neurones

2005 ◽  
Vol 564 (3) ◽  
pp. 877-893 ◽  
Author(s):  
Suzanne I. Sollars ◽  
David L. Hill
Keyword(s):  
Chorda Tympani ◽  
Response Properties ◽  
Taste Response

scholarly journals Response properties of macaque monkey chorda tympani fibers.

1975 ◽  
Vol 66 (6) ◽  
pp. 781-810 ◽  
Author(s):  
M Sato ◽  
H Ogawa ◽  
S Yamashita
Keyword(s):  
Macaque Monkey ◽  
Squirrel Monkeys ◽  
Taste Quality ◽  
Chorda Tympani ◽  
Macaque Monkeys ◽  
Response Properties ◽  
Basic Taste ◽  
Quinine Hydrochloride ◽  
Positive Correlations ◽  
Higher Sensitivity

Many of the chorda tympani fibers of crab-eating monkeys respond to more than one of the four basic stimuli (NaCl, sucrose, HCl, and quinine hydrochloride) as well as cooling or warming of the tongue. Fibers could be classified into four categories depending on their best sensitivity to any one of the four basic stimuli. Sucrose-best and quinine-best fibers are rather specifically sensitive to sucrose and quinine, respectively, while salt-best and acid-best fibers respond relatively well to HCl and NaCl, respectively. Saccharin, dulcin, and Pb acetate produce a good response in sucrose-best fibers, but quinine-best and salt-best fibers also respond to saccharin. Highly significant positive correlations exist between amounts of responses to sucrose and those to saccharin, dulcin, and Pb acetate, indicating that these substances produce in the monkey a taste quality similar to that produced by sucrose. Compared with chroda tympani fibers of rats, hamsters, and squirrel monkeys, macaque monkey taste fibers are more narrowly tuned to one of the four basic taste stimuli and more highly developed in sensitivity to various sweet-tasting substances. Also LiCl and NaCl are more effective stimuli for gustatory receptors in macaque monkeys than NH4Cl and KCl. This contrasts with a higher sensitivity to KCl and NH4Cl than to NaCl in chorda tympani fibers of squirrel monkeys.

Chemical, Electrical and Tactile Sensitivity Changes After Middle Ear Surgery

2020 ◽  
Vol 129 (6) ◽  
pp. 572-577
Author(s):  
Robert Pellegrino ◽  
Thomas Hummel
Keyword(s):  
Middle Ear ◽  
Middle Ear Surgery ◽  
Tactile Sensitivity ◽  
Chorda Tympani ◽  
Ear Surgery ◽  
Taste Response ◽  
Point Pressure ◽  
Sensitivity Changes ◽  
Over Time

Objective/Hypothesis: Taste disturbances are often seen in patients after middle ear surgery due to the stress received by an unprotected chorda tympani. It has also been reported that loss in tactile sensitivity may accompany this issue. The current study was designed to measure electrical, chemical, and tactile sensitives of several senses involved in oral processing, smell, taste and touch, over time. Study Design: Prospective cohort study. Methods: For three time points, one before middle ear surgery and two after operation (about 5 and 23 days), sensitivity thresholds were obtained using electrogustometry (electrical taste), taste strips (chemical taste), Sniffin’ Sticks (smell) and Von Frey Hairs (point-pressure tactile sensitivity). Results: The results show a decline in both chemical and electrical taste responses. Additionally, the electrical taste response showed more sensitivity to deviations and no sign of recovery unlike the chemical taste response. Mechanosensory function of the anterior tongue and olfactory function was not strongly affected by middle ear surgery. Conclusion: Taste responses, but not mechanosensory or olfaction function, are altered after middle ear surgery. Due to the effects that taste loss has on quality of life, gustometry is recommended for this group of patients. Levels of Evidence: 4

Enhancement of gustatory nerve fibers to NaCl and formation of ion channels by commercial novobiocin

1994 ◽  
Vol 266 (5) ◽  
pp. C1165-C1172 ◽  
Author(s):  
A. M. Feigin ◽  
Y. Ninomiya ◽  
S. M. Bezrukov ◽  
B. P. Bryant ◽  
P. A. Moore ◽  
...  
Keyword(s):  
Ion Channels ◽  
Lipid Bilayers ◽  
Neutral Lipids ◽  
Nerve Fibers ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Salt Taste ◽  
Cation Selectivity ◽  
Taste Response ◽  
Gustatory Nerve

Single fibers of the rat chorda tympani nerve were used to study the mechanism of action of the antibiotic novobiocin on salt taste transduction. In the rat, novobiocin selectively enhanced the responses of sodium-specific and amiloride-sensitive chorda tympani nerve fibers (N type) without affecting more broadly responsive cation-sensitive and amiloride-insensitive fibers (E type). In the presence of amiloride, novobiocin was ineffective at enhancing the response of N-type fibers toward sodium chloride. Novobiocin also increased the conductance of bilayers formed from neutral lipids by forming nonrectifying ion channels with low conductance (approximately 7 pS in 110 mM NaCl), long open times (several seconds and longer), and high cation selectivity. Amiloride did not alter either the conductance or kinetics of these novobiocin channels. These observations suggest that even though novobiocin is able to form cation channels in lipid bilayers, and possibly in cell membranes as well, its action on the salt-taste response is through modulation of existing amiloride-sensitive sodium channels.

Chorda tympani taste response of rat to hydrochloric acid subject to voltage-clamped lingual receptive field

1995 ◽  
Vol 268 (5) ◽  
pp. C1295-C1300 ◽  
Author(s):  
J. A. DeSimone ◽  
E. M. Callaham ◽  
G. L. Heck
Keyword(s):  
Receptive Field ◽  
Voltage Clamp ◽  
Paracellular Pathway ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Anionic Sites ◽  
Taste Response ◽  
Nerve Response ◽  
Zero Current ◽  
Positive Voltage

The chorda tympani nerve response of the rat to HCl was obtained with the lingual receptive field under voltage clamp. Unlike NaCl responses, HCl responses were not affected by inside positive voltage perturbations. However, HCl responses under negative voltage clamp were suppressed in contrast to NaCl responses, which were enhanced. Unlike NaCl responses, HCl responses were amiloride insensitive. HCl rinsing from the tongue produced a large off-response. At zero current clamp the off-response coincided with an anomalous increased positive potential. The paracellular resistance was also higher for HCl relative to the same concentration of NaCl. This is evidence that H+ binds to the normally fixed anionic sites of the paracellular pathway rendering it anion selective. It is postulated that release of bound H+ from surface buffer sites is responsible for the second burst of neural activity upon rising HCl. Acids stimulate primarily through the paracellular pathway, which also furnishes buffering sites that regulate H+ concentration, thereby protecting the sensory apparatus from hyperacidic conditions.

scholarly journals ENaC-Dependent Sodium Chloride Taste Responses in the Regenerated Rat Chorda Tympani Nerve After Lingual Gustatory Deafferentation Depend on the Taste Bud Field Reinnervated

2020 ◽  
Vol 45 (4) ◽  
pp. 249-259
Author(s):  
Enshe Jiang ◽  
Ginger D Blonde ◽  
Mircea Garcea ◽  
Alan C Spector
Keyword(s):  
Taste Receptor ◽  
Taste Bud ◽  
Male Rats ◽  
Electrophysiological Recording ◽  
Na Channel ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Response Properties ◽  
Gustatory Nerve ◽  
The Cross

Abstract The chorda tympani (CT) nerve is exceptionally responsive to NaCl. Amiloride, an epithelial Na+ channel (ENaC) blocker, consistently and significantly decreases the NaCl responsiveness of the CT but not the glossopharyngeal (GL) nerve in the rat. Here, we examined whether amiloride would suppress the NaCl responsiveness of the CT when it cross-reinnervated the posterior tongue (PT). Whole-nerve electrophysiological recording was performed to investigate the response properties of the intact (CTsham), regenerated (CTr), and cross-regenerated (CT-PT) CT in male rats to NaCl mixed with and without amiloride and common taste stimuli. The intact (GLsham) and regenerated (GLr) GL were also examined. The CT responses of the CT-PT group did not differ from those of the GLr and GLsham groups, but did differ from those of the CTr and CTsham groups for some stimuli. Importantly, the responsiveness of the cross-regenerated CT to a series of NaCl concentrations was not suppressed by amiloride treatment, which significantly decreased the response to NaCl in the CTr and CTsham groups and had no effect in the GLr and GLsham groups. This suggests that the cross-regenerated CT adopts the taste response properties of the GL as opposed to those of the regenerated CT or intact CT. This work replicates the 5 decade-old findings of Oakley and importantly extends them by providing compelling evidence that the presence of functional ENaCs, essential for sodium taste recognition in regenerated taste receptor cells, depends on the reinnervated lingual region and not on the reinnervating gustatory nerve, at least in the rat.

An analysis of residual NaCl taste response after amiloride

1988 ◽  
Vol 255 (6) ◽  
pp. R1002-R1007 ◽  
Author(s):  
B. K. Formaker ◽  
D. L. Hill
Keyword(s):  
Choline Chloride ◽  
Chorda Tympani ◽  
Chorda Tympani Nerve ◽  
Sodium Salts ◽  
Original Response ◽  
Taste Response ◽  
Electrophysiological Recordings ◽  
Cross Adaptation ◽  
Before And After ◽  
Residual Response

The identity of the residual taste response to NaCl after lingual application of the sodium transport blocker, amiloride, was studied by electrophysiological recordings from the rat chorda tympani nerve. Stimulation of the anterior tongue with salt solutions resulted in responses to halogenated sodium salts that were not eliminated by amiloride; approximately 30% of the halogenated sodium salt response remained after amiloride. In contrast, responses to nonhalogenated sodium salts were reduced to less than 4% of the original response after amiloride. To further learn of characteristics relating to the residual NaCl response, binary mixture and cross-adaptation experiments were accomplished. Responses to mixtures of sodium acetate or sodium bicarbonate with choline chloride were similar to responses elicited by equimolar concentrations of NaCl before and after amiloride. Moreover, NaCl and NaBr cross-adapted with choline chloride after, but not before, lingual application of amiloride. These experiments indicate that the residual response to halogenated sodium salts (e.g., NaCl) is related to the halogen itself, and from findings presented here, we propose one pathway for sodium taste transduction.

Analysis of amiloride inhibition of chorda tympani taste response of rat to NaCl

1985 ◽  
Vol 249 (1) ◽  
pp. R52-R61 ◽  
Author(s):  
J. A. DeSimone ◽  
F. Ferrell
Keyword(s):  
Time Course ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chorda Tympani ◽  
Lingual Epithelium ◽  
Taste Response ◽  
Series Of Experiments ◽  
Kinetics Of ◽  
Kinetics Of Inhibition

The kinetics of inhibition by amiloride of the integrated chorda tympani response were investigated in rats subjected to lingual stimulation with NaCl. In one series of experiments the time of exposure to amiloride was varied at fixed amiloride concentration. Exposure to 10(-4) M amiloride for 2 s reduced the response to 0.5 M NaCl by approximately 50%. The time course of recovery from amiloride inhibition was first order (relaxation time approximately equal to 4 min) for all exposure times. For exposure to 10(-4) M amiloride for less than or equal to 30 s recovery was better than 90% in 20 min. Not all of the chorda tympani response was inhibited by amiloride. With 0.5 M NaCl there was a 70% reduction in response, whereas at 0.05 M NaCl the reduction was only 30%. Parallel effects of amiloride were seen in the short-circuit current of an in vitro preparation of canine lingual epithelium. Amiloride reduced the short-circuit current by the same percentage as it inhibited the chorda tympani response. These results suggest that gustatory transduction is mediated in part by an apical membrane transport system that can be inhibited by amiloride. There exists, however, a second transducing element that is amiloride insensitive. A model is developed, assuming, in part, that the neural response reflects the flows of Na through amiloride-sensitive apical pathways.

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