Tongue Retraction Research Articles

Variation in the feeding kinematics of mole salamanders (Ambystomatidae:Ambystoma)

High-speed cinematography was used to investigate the prey-capture kinematics of six species of mole salamanders (Ambystomatidae). We compared the feeding behavior of the subgenus Ambystoma (A. californiense and A. macrodactylum) with that of the subgenus Linguaelapsus (A. mabeei, A. texanum, A. annulatum, and A. cingulatum). Prey capture by all six species is characterized by a 3-part gape cycle (a period of rapid mouth opening prior to extraoral tongue protraction, followed by a period of relatively stable gape angle during extraoral tongue protraction and retraction, followed by a period of rapid mouth closure), a tongue-extension cycle (protraction and retraction), and anterior head–body displacement. Among the six species, two distinct modes of prey capture are evident: (1) the Ambystoma mode (A. californiense, A. macrodactylum, A. mabeei, and A. texanum), and (2) the Linguaelapsus mode (A. annulatum and A. cingulatum). Most differences in prey-capture kinematics between the two modes are primarily differences of degree rather than the addition or loss of unique behaviors, and include a general reduction in the gape angles and a general increase in the elapsed times associated with specific events in the Linguaelapsus mode. We hypothesize that these differences are primarily the result of a prolonged period of tongue protraction in the Linguaelapsus mode during which the glandular tongue pad is fitted to the prey. In addition to differing from each other, the gape profiles of the ambystomatid subgenera differ markedly from the 4-part gape profiles of plethodontids and salamandrids.

Massive lingual swelling following palatoplasty

We report a case of upper airway obstruction as a result of delayed massive lingual swelling following routine cleft palate repair in an otherwise healthy 12-month-old girl. We believe that ischaemia and venous congestion were the causes of macroglossia, after prolonged use of the Digman Dott tongue retractor. In any difficult and lengthy repair, we recommend the prophylactic insertion of a nasopharyngeal airway under direct vision by the surgeons after surgery to prevent potential upper airway obstruction.

Morphological and kinematic study of the tongue and buccal cavity in the lizard Anguis fragilis (Reptilia:Anguidae).

The ability to detect chemical cues is highly developed in Scleroglossa, and particularly in anguid lizards. This ability was predicted because anguids possess a well-developed vomeronasal organ (VNO) (or Jacobson's organ) and rely largely on chemical cues in various behaviours as other active foragers. In this work, we have investigated the possible functional association between tongue flicking and the VNO in the lizard Anguis fragilis. The morphology of the tongue and the buccal cavity was investigated by light and scanning electron microscopy. The kinematics of tongue and jaw movements was studied by high speed cinematography. The epithelial cells of the ventral aspect of the tongue tips show microstructures (microridges, microfacets, micropores) which are not present on other areas of the mouth. Beneath the tongue, the floor of the buccal cavity shows two concave-like elevations suggesting a structural analogy with the anterior processes described in snakes. The apex and the internal margin of these processes bear parallel oblique ridges. Taste buds occur anteriorly on the buccal floor and on the palate and are abundant on the internal side and on the edge on the anterior processes. The tongue showed three modes of tongue flicking: simple downward extension, single oscillation, and multiple oscillations. At each tongue flick, the ventral surface of the tips was observed contacting the substratum. Immediately after the tongue retraction, the buccal floor moved slightly upward. The observation of tongue flicking with the mouth open showed that the anterior processes moved upward when the tongue was retracted. These observations suggest that following: 1) during tongue flicking the ventral surface of the tongue tips invariably makes contact with the substratum; 2) the microstructures of the tongue tips and the ridges of the anterior processes might be helpful for collecting and receiving, respectively, chemicals during tongue flicking; 3) the anterior processes may be apposed on the roof of the mouth next to the ducts of VNOs when the buccal floor is fully elevated; 4) due to their localization, the taste buds could be equally stimulated by the molecules transferred during tongue flicking.

Aerodynamic Evidence for Articulatory Overlap in Korean

Abstract Aerodynamic evidence indicates the existence of overlapped labial//velar sequences in Korean. Oral pressure readings for [ipku] show a brief rarefaction in oral pressure during the consonantal sequence, indicating that tongue retraction during a front-back vowel sequence occurs simultaneously with full closures at the labial and velar places of articulation. This confluence of phenomena results in the observed pressure rarefaction due to expansion of the sealed oral cavity. Similarly, pressure readings for [upki] show a brief, marked increase during the consonantal sequence, indicating that tongue advancement during a back-front vowel sequence temporally overlaps with full closures at both the labial and velar places of articulation. This results in a pressure increase due to contraction of the sealed oral cavity. To our knowledge, the present study is the first to demonstrate consonant coproduction in terms of oral pressure, and to report on coarticulatory effects involving four sequenced segments.

The Modulation of Feeding Behavior in Response to Prey Type in the Frog Rana Pipiens

ABSTRACT Using high-speed video motion analysis, the kinematics of feeding behavior was studied in Rana pipiens. Rana pipiens exhibits differing behavior patterns depending upon prey type. When feeding on small prey such as waxworms, R. pipiens uses tongue protraction to catch prey, minimizing head and body movements. When feeding on the larger earthworm, it arches its body, flexes the head downwards and uses jaw prehension to capture the prey. Time to completion of tongue retraction, time to completion of mouth closing, duration of tongue retraction, duration of mouth closing, total time that the mouth is open and maximum tongue reach were significantly longer during waxworm feedings than during earthworm feedings. The tongue angle and degree of head flexion were significantly greater during earthworm feedings. These different kinematic patterns correspond to differences in feeding behavior among major taxa of anurans. Phylogenetically primitive archaeobatrachian frogs have short tongues which can be protracted only a few millimeters. In contrast, many neobatrachians have long tongues which they project to catch small prey. The similarity between the behavior that neobatrachians use to catch large prey and the movement patterns of archaeobatrachians suggests that Rana pipiens has retained the plesiomorphic archaeobatrachian motor pattern and uses it to catch large prey, while evolving a new motor pattern for catching small prey.

The Mechanism Of Tongue Projection In Chameleons: I. Electromyographic Tests Of Functional Hypotheses

ABSTRACT In this paper we document the activity of key muscles of the tongue, hyobranchia! apparatus and head during prey capture in the lizard Chamaeleo jacksonii Boulenger and use these data to test current hypotheses of chameleon tongue function. Electromyographic recordings were made during 27 feedings from nine individuals and synchronized with high-speed video recordings (200fields s−1), permitting an assessment of the activity of muscles relative to the onset of tongue projection, contact between tongue and prey, and tongue retraction. Four major results were obtained. (1) The hyoglossi muscles exhibit a single burst of activity that begins between 10 ms before and 20 ms after the onset of tongue projection and continues throughout the period of tongue retraction. (2) The accelerator muscle exhibits a biphasic activity pattern, with the first burst lasting about 185 ms and ending an average of 10.6 ms prior to the onset of projection. (3) The accelerator muscle shows regional variation in morphology that corresponds with variation in motor pattern. The anterior region of the muscle, unlike the posterior portion, exhibits only a single burst of activity that begins 2.5 ms after the onset of tongue projection and is thus not involved in launching the tongue. (4) The geniohyoidei, sternohyoidei, sternothyroidei, depressor mandibulae, adductor mandibulae and pterygoideus all exhibit activity patterns consistent with previously reported kinematic patterns and their proposed roles. The major implications of these results for models of the chameleon feeding mechanism are (1) that the hyoglossi do not act to hold the tongue on the entoglossal process during a loading period prior to tongue projection, and (2) that the presence of 185 ms of intense activity in the accelerator muscle prior to tongue projection suggests the presence of a preloading mechanism, the nature of which is the subject of the companion paper.

Trajectory surgical guide stent for implant placement

This article describes a new implant placement surgical guide that gives both implant location and trajectory to the surgeon. Radiopaque markers are placed on diagnostic dentures and a lateral cephlometric radiograph is made that shows the osseous anatomy at the symphysis and the anterior tooth location. The ideal implant location and trajectory data are transferred to a surgical stent that programs the angle and location of the fixtures at time of surgery. The stent has the additional benefit of acting as an occlusion rim, a mouth prop, and tongue retractor. Use of this stent has resulted in consistently programming the placement of implant fixtures that are prosthodontically ideal.

Kinematics of prey capture in the tailed frog Ascaphus truei (Anura: Ascaphidae)

The kinematics of prey capture by Ascaphus truei was investigated. High-speed films (100 fps) of 13 successful and one unsuccessful prey capture sequences from six adult frogs were analysed. Ascaphus, the sister group of all living frogs, shares several aspects of feeding kinematics, including rotation of the tongue pad about the mandibular symphysis and mandibular bending during mouth opening and closing, with more derived frogs such as Bufo marinus. The times required for tongue retraction, mouth opening and closing are similar in Ascaphus and Bufo. However, because Bufo is much larger and protracts its tongue much farther than Ascaphus, the velocities of tongue retraction, mouth opening and mouth closing are relatively lower in Ascaphus than in Bufo. Differences in prey capture between Ascaphus and Bufo marinus are (1) the distance of tongue protraction is less in Ascaphus (±0.5 cm) than in Bufo (c. 2 cm); and (2) lunging of the whole body is more pronounced in Ascaphus. Prey capture is highly variable in Ascaphus. An intraoral transport sequence is sometimes (7 of 14 observations) inserted into the prey capture cycle before the completion of mouth closing. The gape cycles range from 80–150 ms for sequences with no oral transport and from 130–280 ms for sequences with oral transport. Also, the time required for tongue retraction is significantly longer in the unsuccessful capture attempt. This variability is generally greater than that observed during prey capture in salamanders, and suggests that frogs and salamanders may differ in the importance of sensory feedback in coordinating prey capture.

Kinematics of Tongue Projection in Chamaeleo Oustaleti

The kinematics of prey capture by the chamaeleonid lizard Chamaeleo oustaleti were studied using high-speed cinematography. Three feeding sequences from each of two individuals were analyzed for strike distances of 20 and 35 cm, at 30°C. Ten distances and angles were measured from sequential frames beginning approximately 0.5 s prior to tongue projection and continuing for about 1.0 s. Sixteen additional variables, documenting maximum excursions and the timing of events, were calculated from the kinematic profiles. Quantified descriptions of head, hyoid and tongue movements are presented. Previously unrecognized rapid protraction of the hyobranchial skeleton simultaneously with the onset of tongue projection was documented and it is proposed that this assists the accelerator muscle in powering tongue projection. Acceleration of the tongue occurred in about 20ms, reaching a maximum acceleration of 486 m s−2 and maximum velocity of 5.8m s−1 in 35 cm strikes. Deceleration of the tongue usually began within 5 ms before prey contract and the direction of tongue movement was reversed within 10 ms of prey contact. Retraction of the tongue, caused by shortening of the retractor muscles, reached a maximum velocity of 2.99 ms−1 and was complete 330 ms after prey contact. Projection distance influences many aspects of prey capture kinematics, particularly projection time, tongue retraction time and the extent of gape and head movements during tongue retraction, all of which are smaller in shorter feedings. Though several features of the chameleon strike have apparently been retained from lizards not capable of ballistic tongue projection, key differences are documented. Unlike members of a related family, the Agamidae, C. oustaleti uses no body lunge during prey capture, exhibits gape reduction during tongue projection and strongly depresses the head and jaws during tongue retraction. Note: Present address: Department of Biological Sciences, Florida State University, Tallahassee, FL 32306, USA.

Synaptic efficacy of inhibitory synapses in the reinnervating hypoglossal motoneurons

The synaptic efficacy of inhibitory synapses in tongue protruder motoneurons reinnervating the tongue retractor muscle was studied in cats. We have demonstrated that the percentage magnitude of a short- and a long-lasting inhibitory postsynaptic potential in the inhibitory postsynaptic potentials produced in the tongue protruder motoneurons, whose axons had been cut but allowed to regenerate to make functional contact with the tongue retractor muscles, by lingual nerve or inferior alveolar nerve stimulation, was rearranged to appear like that exhibited by the tongue retractor motoneurons that normally supply that muscle. In addition, the peak amplitude of the summated afterhyperpolarization in a tongue protruder motoneuron on operated cats at nine months axon-union was in the normal range.

Excitatory phenomena following the use of propofol in dogs

Over a two month period, 148 dogs presented for surgery had general anaesthesia induced and sometimes maintained with propofol. Excitatory phenomena were recorded on 12 occasions. Signs included muscle twitching, opisthotonus and limb hyperextension (nine cases), and panting with associated activity of the brachiocephalicus muscle and tongue retraction (three cases). The records for a similar two month period were examined for data and observations relating to thiopentone. During this period anaesthesia was induced with thiopentone in 71 dogs and no excitatory phenomena were recorded.

The strike of the tiger salamander: quantitative electromyography and muscle function during prey capture

1. We provide a quantitative description of the motor pattern of 11 cranial muscles that control terrestrial prey capture behavior via tongue projection in the tiger salamander (Ambystoma tigrinum) and test the hypothesis that the cranial motor pattern does not differ between successful and unsuccessful strikes. 2. Simultaneous high-speed video images and electromyograms from cranial muscles were recorded during prey capture by 4 individuals. Neither the time to prey contact by the tongue nor gape cycle duration during the strike were significantly different between successful and unsuccessful strikes. In addition, 76 out of 77 parameters measured from 11 cranial muscle electromyograms during the strike showed no significant differences between successful and unsuccessful captures. We conclude that the strike of the tiger salamander shows little variability under these experimental conditions. 3. During the strike all head muscles have nearly synchronous onsets of electromyographical activity. The subarcualis rectus 1 muscle exhibits two bursts of activity: one during tongue projection and a second during tongue retraction. The genioglossus and interhyoideus muscles both show sharp single peaks of activity during the tongue projection phase. The depressor mandibulae muscle typically shows a second peak in activity coincident with the plateau phase of the gape cycle.

Quantitative analysis of prey-capture kinematics in Anolis equestris (Reptilia: Iguanidae)

High-speed cinematography was employed to study the mechanics of prey capture in Anolis equestris. Capture of live prey (adult locusts) consists of a cyclic movement of the upper and lower jaws combined with tongue protraction. Kinematic profiles are presented for the jaws, tongue, and forelimbs. The tongue is projected during the "slow open" stage and most of the "fast open" stage. The tongue protrudes beyond the mandibular symphysis during the slow open stage, and rotates simultaneously around a transverse anteromedian axis. The prey is thus contacted by the dorsal sticky surface of the tongue, and then pulled backward into the oral cavity by a combination of a forward movement of the jaws and retraction of the tongue. Gape angle, defined as the angle between the upper and lower jaws, continues to increase during the initial stages of tongue retraction. During the capture process, the anterior part of the body lunges forward, followed by a return to its original position; this displacement is mediated by the forelimbs, which usually remain well anchored to the floor. The cyclic food-capture movements of the jaws and tongue–hyoid system in A. equestris (Iguanidae) and Chameleo dilepis (Chamaeleontidae) are compared. I argue that one of the primary selection forces in the evolution of the different mechanisms of prey prehension in these two lizard groups was enhancement of the locomotor system and, consequently, foraging ability.

The Activity of the Cricothyroid Muscle and the Intrinsic Fundamental Frequency in Danish Vowels

The relationship between the electromyographic (EMG) activity from the pars obliqua of the cricothyroid (CT) muscle (recorded with bipolar hook-wire electrodes) and the intrinsic fundamental frequency (IF0) in high and low vowels in Danish was investigated. The test material, which consisted of 306 randomized natural words of the type C'V(:)le, imbedded in carrier sentences, was recorded by 4 native speakers of Danish. The following vowel pairs were compared: ['i-'a,'i:-'ae:, 'u:-'ae:] and ['i:-'a]. The results, which are based on visual inspection of average EMG and fundamental frequency (F0) curves, show a positive correlation between the CT activity and IF0, more specifically that the CT activity rise related to the high vowels starts earlier and in most cases more steeply than the CT activity related to the low vowels. However, a drop in F0 at the beginning of the low vowels cannot be accounted for by CT activity. This F0 drop is believed to be the result of either tongue retraction during the articulation or influence from the preceding consonant. The following conclusion is drawn: The CT muscle is a major factor in controlling IF0 in stressed high and low vowels in Danish.

Synaptic efficacy of inhibitory synapses and repetitive firing in the reinnervating trigeminal and hypoglossal motoneurons

The synaptic efficacy and repetitive firing in masseteric motoneurons after the self-union operation and in tongue protruder motoneurons after their cut axons were reunited to tongue retractor muscles, the styloglossus muscle, were studied in cats. To ensure the correct identification of reinnervating motoneurons, the muscle response produced by an induced spike in a motoneuron by intracellularly injected depolarizing current was recorded. In both masseteric and tongue protruder motoneurons there were no differences on the patterns of postsynaptic potentials produced in reinnervating and non-reinner-vating motoneurons by peripheral nerve stimulation, suggesting that the recovery of the synaptic efficacy of inhibitory synapses is time-dependent rather than muscle reinnervation. However, the present study demonstrated that the recovery of processes that control rhythmical firing of motoneurons is probably dependent on muscle reinnervation.

Activity of extrinsic tongue muscle during swallowing in sheep

The participation of extrinsic muscles of the tongue in swallowing reflexly induced by stimulation of the superior laryngeal nerve was studied in 7 anesthetized sheep. The tongue retractor muscles (styoglossus and hyyoglossus) always discharged in synergy with the suprahyoid (geniohyoid) and jaw (anterior digastric medial pterygoid) muscles. The main protrusor muscle of the tongue, the genioglossus, was inactive in 5 animals and active in 2. The significance of this muscular synergy is discussed.

Hyolingual feeding systems of the Plethodontidae: Comparative kinematics of prey capture by salamanders with free and attached tongues

AbstractHigh‐speed cinematography (500 fps) was used to analyze quantitatively the kinematics of terrestrial prey capture in Bolitoglossa occidentalis, B. mexicana, Ensatina esch‐scholtzii, Plethodon glutinosus, Desmognathus quadramaculatus, Hynobius kimurae, and H. nebulosus. The gape cycle of these salamanders is highly stereotyped. In B. occidentalis the mouth is opened by a combination of cranial elevation and mandibular depression. The gape increases dramatically during tongue retraction, thus allowing the prey to be delivered to the rear of the oral cavity without being impeded by the marginal teeth. The absence of a feeding function for these teeth apparently has resulted in their reduction and/or morphological alteration in some bolitoglos‐sines. Observed differences in jaw rotation between successful and unsuccessful prey capture attempts appear to be biomechanical phenomena and not adjustments by the salamander in response to neural feedback.Tongue projection is most rapid and highly accurate in the two bolitoglossines and Ensatina. The distance to which the tongue can be protracted from the mouth is 7% snout‐vent length in D. quadramaculatus, P. glutinosus, H. kimurae, and H. nebulosus (attached protrusible tongue); 15% in E. eschscholtzii (attached projectile tongue); and 30% in B. occidentalis (free projectile tongue). Even though tongue protraction is significantly faster in salamanders with projectile tongues than those with protrusible tongues, the range of times for the entire gape cycle is generally similar for all salamanders (ca. 100 ms). However, less derived salamanders spend a shorter period preparing the tongue for firing and more time in its projection than E. eschscholtzii and B. occidentalis. One obvious advantage for increasing the speed of tongue protraction is that it decreases the prey's available escape time. In the supergenus Bolitoglossa prey are limited to small, active invertebrates by a combination of stereotyped feeding behavior, a small tongue pad, and a lightweight hyolingual apparatus that is projected extremely fast.While all terrestrial salamanders possess the same basic feeding system, the bolitoglossines have evolved an impressive array of unique specializations for capturing small, rapidly moving prey. This suite of characters has enabled the tribe to radiate rapidly into a vast variety of microhabitats.

Effect of sensory input from the tongue on jaw movement in normal feeding in the opossum.

Opossums were presented with solid and liquid foods. The movements of the jaw and tongue were recorded cineradiographically together with recordings of the EMG activity in muscles opening the jaw and moving the base of the tongue (hyoid). The jaw opening in each cycle was in two stages--01 and 02; 01 had a constant amplitude irrespective of the food ingested. Ingestion of liquid (which involved continuous accumulation of a liquid bolus in the valleculae prior to swallowing) was associated with cycles of oral movement in which 02 was small; tongue retraction was associated with this opening. In contrast, solid and semisolid food ingestion was associated with large angles of jaw opening in 02 that also coincided with the tongue retraction. In this latter case a characteristic pattern of EMG activity, in which all the muscles moving the hyoid were simultaneously active, was added to the pattern seen in lapping; this additional activity had an EMG pattern that was consistent with a jaw opening reflex. The findings contrast with other reports that the jaw opening reflex is suppressed in mastication. Experimentally induced tongue contact with a variety of solid surfaces during lapping (an activity involving accumulation of a liquid bolus in the valleculae) induced neither increased jaw opening nor the additional EMG pattern. However, in situations when there was no bolus in the valleculae, additional jaw opening activity was elicited when the tongue contracted solids intra- or extra-orally. It is suggested that the ability of sensory input, from the anterior tongue, to elicit a jaw opening reflex and to change the type of jaw/tongue cycle was dependent upon the extent of bolus accumulation in the valleculae and therefore indirectly upon the consistency of the food.

Mechanics and Neuromorphology of Feeding in Amphibians

Salamanders and frogs exhibit strong similarities in their habitats, prey preferences and foraging strategies. Despite these similarities, they differ profoundly in the structure and function of the adult feeding apparatus, and in the participation of cranial and spinal nerves and nuclei in the control of feeding behavior. In frogs, the hyolingual skeleton plays no role in tongue projection. Only the tongue is projected out of the mouth under the control of the nn. trigeminus (tongue protraction) and hypoglossus (tongue protraction and retraction). In all salamanders, feeding is based on forward movement of the hyolingual apparatus, which is folded into a slender, far-reaching projectile in the most highly derived salamanders. Tongue protraction is controlled by nn. glossopharyngeus and vagus, and tongue retraction is controlled by the first and second spinal nerves. All muscles related to feeding are activated sequentially in frogs and simultaneously in salamanders. While the descending pathways to the brainstem and cervical spinal motor nuclei are similar in frogs and salamanders, differences in muscle function and activation pattern imply that the premotor reticular formation is also different. In frog tadpoles and salamander larvae, the hyobranchial apparatus plays different roles in feeding and breathing. This has led to differential loss, acquisition and change of function of musculoskeletal elements during the ontogeny and phylogeny of the adult feeding apparatus in frogs and salamanders. These differences in the musculoskeletal periphery imply that a reorganization at or above the level of the reticular formation is likely to have occurred in frogs, but not in salamanders.

Excitatory and inhibitory postsynaptic potentials in cat hypoglossal motoneurons during swallowing.

The postsynaptic potentials produced in cat genioglossus and styloglossus motoneurons (GG- and SG-Mns) during swallowing were studied. During swallowing elicited by placing water on the dorsum of the tongue, the GG-muscle discharged for 80-210 ms (mean +/- S. D. 123 +/- 31 ms, N = 59) and was abruptly suppressed, and the SG-muscle began discharging in synchrony with the GG-muscle and discharged for 200-360 ms (mean +/- S. D. 247 +/- 36 ms, N = 59). The GG- and the SG-Mns were identified if unitary muscle activity followed the induced spike of the motoneuron one-for-one. During swallowing, excitatory postsynaptic potentials (EPSPs) were evoked in the SG-Mns regardless of the respiratory drive on the SG-Mns, and inhibitory postsynaptic potential (IPSP) or EPSP-IPSP was evoked on the GG-Mns regardless of the respiratory drive on the GG-Mns. By increasing the intracellular concentration of chloride ions, the IPSP elicited in the GG-Mn during swallowing was turned into a depolarizing potential. In immobilized cats, a depolarizing potential and a depolarizing-hyperpolarizing potential sequence was evoked successively on a tongue retractor motoneuron and a tongue protruder motoneuron by repetitive electrical stimulation of the superior laryngeal nerve.