Experimental Demonstration of Tongue Muscle Origin in Chick Embryos

Development ◽  
1958 ◽  
Vol 6 (4) ◽  
pp. 527-529
Author(s):  
E. M. Deuchar
Keyword(s):  
Chick Embryos ◽  
Occipital Region ◽  
Experimental Demonstration ◽  
Tongue Muscle ◽  
Segmental Nerve ◽  
Reptile Species ◽  
Tongue Muscles ◽  
Mammalian Embryos ◽  
Muscle Origin

Since in all classes of vertebrates the tongue muscles are innervated by nerve XII, a segmental nerve of the occipital region, it is usually argued on this criterion alone that they originate from occipital myotome tissue. Descriptive evidence in support of this generalization is, however, far from adequate. The most complete accounts that exist refer to one amphibian and two reptile species. In the amphibian Necturus, Platt (1897) observed that ventral outgrowths of the 3rd and 4th occipital myotomes became tongue muscles, and Edgeworth (1935) has described the development of tongue muscles in the reptiles Sphenodon and Lacerta, from ventral parts of two occipital and two cervical myotomes, all innervated by nerve XII. In avian and mammalian embryos, however, early muscle rudiments are extremely difficult to recognize with any certainty histologically.

scholarly journals Progressive Protrusive Tongue Exercise Does Not Alter Aging Effects in Retrusive Tongue Muscles

2021 ◽  
Vol 12 ◽  
Author(s):  
Tiffany J. Glass ◽  
Joanie E. Figueroa ◽  
John A. Russell ◽  
Brittany N. Krekeler ◽  
Nadine P. Connor
Keyword(s):  
Rat Model ◽  
Contractile Properties ◽  
Brown Norway ◽  
Fiber Types ◽  
Tongue Muscle ◽  
Muscle Contractile Properties ◽  
Exercise Regimen ◽  
Tongue Muscles ◽  
Muscle Contractile ◽  
Progressive Resistance

Purpose: Exercise-based treatment approaches for dysphagia may improve swallow function in part by inducing adaptive changes to muscles involved in swallowing and deglutition. We have previously shown that both aging and progressive resistance tongue exercise, in a rat model, can induce biological changes in the genioglossus (GG); a muscle that elevates and protrudes the tongue. However, the impacts of progressive resistance tongue exercise on the retrusive muscles (styloglossus, SG; hyoglossus, HG) of the tongue are unknown. The purpose of this study was to examine the impact of a progressive resistance tongue exercise regimen on the retrusive tongue musculature in the context of aging. Given that aging alters retrusive tongue muscles to more slowly contracting fiber types, we hypothesized that these biological changes may be mitigated by tongue exercise.Methods: Hyoglossus (HG) and styloglossus (SG) muscles of male Fischer 344/Brown Norway rats were assayed in age groups of young (9 months old, n = 24), middle-aged (24 months old, n = 23), and old (32 months old, n = 26), after receiving an 8-week period of either progressive resistance protrusive tongue exercise, or sham exercise conditions. Following exercise, HG and SG tongue muscle contractile properties were assessed in vivo. HG and SG muscles were then isolated and assayed to determine myosin heavy chain isoform (MyHC) composition.Results: Both retrusive tongue muscle contractile properties and MyHC profiles of the HG and SG muscles were significantly impacted by age, but were not significantly impacted by tongue exercise. Old rats had significantly longer retrusive tongue contraction times and longer decay times than young rats. Additionally, HG and SG muscles showed significant MyHC profile changes with age, in that old groups had slower MyHC profiles as compared to young groups. However, the exercise condition did not induce significant effects in any of the biological outcome measures.Conclusion: In a rat model of protrusive tongue exercise, aging induced significant changes in retrusive tongue muscles, and these age-induced changes were unaffected by the tongue exercise regimen. Collectively, results are compatible with the interpretation that protrusive tongue exercise does not induce changes to retrusive tongue muscle function.

Anatomic consequences of intrinsic tongue muscle activation

2006 ◽  
Vol 101 (5) ◽  
pp. 1377-1385 ◽  
Author(s):  
E. Fiona Bailey ◽  
Yu-Hsien Huang ◽  
Ralph F. Fregosi
Keyword(s):  
Electrical Stimulation ◽  
Muscle Activation ◽  
Critical Role ◽  
Upper Airway ◽  
Pressure Source ◽  
Airway Patency ◽  
Tongue Muscle ◽  
Airway Pressures ◽  
Tongue Muscles ◽  
Spontaneously Breathing

We recently showed respiratory-related coactivation of both extrinsic and intrinsic tongue muscles in the rat. Here, we test the hypothesis that intrinsic tongue muscles contribute importantly to changes in velopharyngeal airway volume. Spontaneously breathing anesthetized rats were placed in a MRI scanner. A catheter was placed in the hypopharynx and connected to a pressure source. Axial and sagittal images of the velopharyngeal airway were obtained, and the volume of each image was computed at airway pressures ranging from +5.0 to −5.0 cmH2O. We obtained images in the hypoglossal intact animal (i.e., coactivation of intrinsic and extrinsic tongue muscles) and after selective denervation of the intrinsic tongue muscles, with and without electrical stimulation. Denervation of the intrinsic tongue muscles reduced velopharyngeal airway volume at atmospheric and positive airway pressures. Electrical stimulation of the intact hypoglossal nerve increased velopharyngeal airway volume; however, when stimulation was repeated after selective denervation of the intrinsic tongue muscles, the increase in velopharyngeal airway volume was significantly attenuated. These findings support our working hypothesis that intrinsic tongue muscles play a critical role in modulating upper airway patency.

scholarly journals Synchronization of presynaptic input to motor units of tongue, inspiratory intercostal, and diaphragm muscles

2011 ◽  
Vol 105 (5) ◽  
pp. 2330-2336 ◽  
Author(s):  
Amber Rice ◽  
Andrew J. Fuglevand ◽  
Christopher M. Laine ◽  
Ralph F. Fregosi
Keyword(s):  
Motor Neuron ◽  
Motor Unit ◽  
Motor Units ◽  
Excitatory Input ◽  
Respiratory Drive ◽  
Tongue Muscle ◽  
Motoneuron Pool ◽  
Hypoglossal Motoneuron ◽  
Tongue Muscles ◽  
Premotor Neurons

The respiratory central pattern generator distributes rhythmic excitatory input to phrenic, intercostal, and hypoglossal premotor neurons. The degree to which this input shapes motor neuron activity can vary across respiratory muscles and motor neuron pools. We evaluated the extent to which respiratory drive synchronizes the activation of motor unit pairs in tongue (genioglossus, hyoglossus) and chest-wall (diaphragm, external intercostals) muscles using coherence analysis. This is a frequency domain technique, which characterizes the frequency and relative strength of neural inputs that are common to each of the recorded motor units. We also examined coherence across the two tongue muscles, as our previous work shows that, despite being antagonists, they are strongly coactivated during the inspiratory phase, suggesting that excitatory input from the premotor neurons is distributed broadly throughout the hypoglossal motoneuron pool. All motor unit pairs showed highly correlated activity in the low-frequency range (1–8 Hz), reflecting the fundamental respiratory frequency and its harmonics. Coherence of motor unit pairs recorded either within or across the tongue muscles was similar, consistent with broadly distributed premotor input to the hypoglossal motoneuron pool. Interestingly, motor units from diaphragm and external intercostal muscles showed significantly higher coherence across the 10–20-Hz bandwidth than tongue-muscle units. We propose that the lower coherence in tongue-muscle motor units over this range reflects a larger constellation of presynaptic inputs, which collectively lead to a reduction in the coherence between hypoglossal motoneurons in this frequency band. This, in turn, may reflect the relative simplicity of the respiratory drive to the diaphragm and intercostal muscles, compared with the greater diversity of functions fulfilled by muscles of the tongue.

scholarly journals Influence of tongue muscle contraction and transmural pressure on nasopharyngeal geometry in the rat

2011 ◽  
Vol 111 (3) ◽  
pp. 766-774 ◽  
Author(s):  
Ralph F. Fregosi
Keyword(s):  
Muscle Contraction ◽  
Negative Pressure ◽  
Tongue Muscle ◽  
Pharyngeal Airway ◽  
Pharyngeal Pressure ◽  
Obstructive Sleep ◽  
Pharyngeal Muscles ◽  
Tongue Muscles ◽  
Shape Ratio ◽  
Stimulation Of

The mammalian pharynx is a hollow muscular tube that participates in ingestion and respiration, and its size, shape, and stiffness can be altered by contraction of skeletal muscles that lie inside or outside of its walls. MRI was used to determine the interaction between pharyngeal pressure and selective stimulation of extrinsic tongue muscles on the shape of the rat nasopharynx. Pressure (−9, −6, −3, 3, 6, and 9 cmH2O) was applied randomly to the isolated pharyngeal airway of anesthetized rats that were positioned in a 4.7-T MRI scanner. The anterior-posterior (AP) and lateral diameters of the nasopharynx were measured in eight axial slices at each level of pressure, with and without bilateral hypoglossal nerve stimulation (0.1-ms pulse, 1/3 maximal force, 80 Hz). The rat nasopharynx is nearly circular, and positive pharyngeal pressure caused similar expansion of AP and lateral diameters; as a result, airway shape (ratio of lateral to AP diameter) remained constant. Negative pressure did not change AP or lateral diameter significantly, suggesting that a negative pressure reflex activated the tongue or other pharyngeal muscles. Stimulation of tongue protrudor muscles alone or coactivation of protrudor and retractor muscles caused greater AP than lateral expansion, making the nasopharynx slightly more elliptical, with the long axis in the AP direction. These effects tended to be more pronounced at negative pharyngeal pressures and greater in the caudal than rostral nasopharynx. These data show that stimulation of rodent tongue muscles can adjust pharyngeal shape, extending previous work showing that tongue muscle contraction alters pharyngeal compliance and volume, and provide physiological insight that can be applied to the treatment of obstructive sleep apnea.

scholarly journals Genioglossus and Intrinsic Electromyographic Activities in Impeded and Unimpeded Protrusion Tasks

2009 ◽  
Vol 101 (1) ◽  
pp. 276-282 ◽  
Author(s):  
Lora J. Pittman ◽  
E. Fiona Bailey
Keyword(s):  
Motor Unit ◽  
Biomechanical Model ◽  
Force Transducer ◽  
Single Motor Unit ◽  
Genioglossus Muscle ◽  
Tongue Muscle ◽  
Single Motor ◽  
Human Tongue ◽  
Tongue Muscles ◽  
Tongue Position

Eight muscles invest the human tongue: four extrinsic muscles have external origins and insert into the tongue body and four intrinsic muscles originate and terminate within the tongue. Previously, we noted minimal activation of the genioglossus tongue muscle during impeded protrusion tasks (i.e., having subjects push the tongue against a force transducer), suggesting that other muscles play a role in the production of tongue force. Accordingly, we sought to characterize genioglossus tongue muscle activities during impeded and unimpeded protrusion tasks (i.e., having subjects slowly and smoothly move the tongue out of their mouth). Electromyographic (EMG) and single motor-unit potentials of the extrinsic genioglossus muscle were recorded with tungsten microelectrodes and EMG activities of intrinsic tongue muscles were recorded with hook-wire electrodes inserted into the anterior tongue body. Tongue position was detected by an isotonic transducer coupled to the tongue tip. Protrusive force was detected by a force transducer attached to a rigid bar. Genioglossus and intrinsic tongue muscles were simultaneously active in both impeded and unimpeded protrusion tasks. Genioglossus whole muscle EMG and single motor-unit activities changed faithfully as a function of tongue position, with increased discharge associated with protrusion and decreased discharge associated with retraction back to the rest position. In contrast, during the impeded protrusion task drive the genioglossus muscle remained constant as protrusion force increased. Conversely, intrinsic tongue muscle activities appropriately followed changes in both tongue position and force. Importantly, we observed significantly higher levels of intrinsic muscle activity in the impeded protrusion task. These observations suggest that protrusion of the human tongue requires activation of the genioglossus and intrinsic protrudor muscles, with the former more important for establishing anterior–posterior tongue location and the latter playing a greater role in the generation of protrusive force. A biomechanical model of these actions is provided and discussed.

scholarly journals Atlas-Based Tongue Muscle Correlation Analysis From Tagged and High-Resolution Magnetic Resonance Imaging

2019 ◽  
Vol 62 (7) ◽  
pp. 2258-2269
Author(s):  
Fangxu Xing ◽  
Maureen Stone ◽  
Tessa Goldsmith ◽  
Jerry L. Prince ◽  
Georges El Fakhri ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
High Resolution ◽  
Sound Production ◽  
Vocal Tract ◽  
Speech Sound ◽  
Resonance Imaging ◽  
En Bloc ◽  
Tongue Muscle ◽  
Tongue Muscles

Purpose Intrinsic and extrinsic tongue muscles in healthy and diseased populations vary both in their intra- and intersubject behaviors during speech. Identifying coordination patterns among various tongue muscles can provide insights into speech motor control and help in developing new therapeutic and rehabilitative strategies. Method We present a method to analyze multisubject tongue muscle correlation using motion patterns in speech sound production. Motion of muscles is captured using tagged magnetic resonance imaging and computed using a phase-based deformation extraction algorithm. After being assembled in a common atlas space, motions from multiple subjects are extracted at each individual muscle location based on a manually labeled mask using high-resolution magnetic resonance imaging and a vocal tract atlas. Motion correlation between each muscle pair is computed within each labeled region. The analysis is performed on a population of 16 control subjects and 3 post–partial glossectomy patients. Results The floor-of-mouth (FOM) muscles show reduced correlation comparing to the internal tongue muscles. Patients present a higher amount of overall correlation between all muscles and exercise en bloc movements. Conclusions Correlation matrices in the atlas space show the coordination of tongue muscles in speech sound production. The FOM muscles are weakly correlated with the internal tongue muscles. Patients tend to use FOM muscles more than controls to compensate for their postsurgery function loss.

Changes in Hepatocytes Following Decapitation of Chick Embryos

1968 ◽  
Vol 26 ◽  
pp. 228-229
Author(s):  
William E. Dossel
Keyword(s):  
Glycogen Content ◽  
Morphological Evidence ◽  
Chick Embryos ◽  
Embryonic Chick ◽  
Intrauterine Development ◽  
Endocrine Organs ◽  
Mammalian Embryos ◽  
Glycogen Deposition ◽  
Glycogen Particles

Deposition of glycogen in embryonic chick livers begins during the 6th day of incubation, and continues until day 10 when the stored glycogen begins to disappear; depletion of reserves is most evident on day 12. On day 14, glycogen reappears and increases up to hatching. Hypophysectomy, by means of decapitation of the embryo at 33 hours, eliminates the period of depletion and prevents the onset of function in the embryonic endocrine organs as well. Glycogen deposition in hepatocytes of mammalian embryos occurs throughout intrauterine development, but can be interrupted by decapitation.This EM-based investigation provides morphological evidence supporting conclusions reached in earlier studies wherein glycogen content of livers from normal and decapitated 12 day-old embryos was assayed chemically (2). In livers of normal embryos, glycogen fields (i.e. accumulations of alpha and beta glycogen particles, related to agranular reticulum), appeared infrequently in hepatocytes throughout the liver (fig. 2) while in those of decapitated embryos, glycogen fields were abundant and characteristically composed of heavy accumulations of glycogen (fig. 3).

The Bioavailability of Substances Administered to Chick Embryos: The Maximum Effective Route of Administration

1997 ◽  
Vol 25 (6) ◽  
pp. 655-665
Author(s):  
Drahomír Veselý ◽  
Doubravka Veselá ◽  
Richard Jelínek
Keyword(s):  
Palmitic Acid ◽  
Culture Media ◽  
Developmental Toxicity ◽  
Avian Embryo ◽  
In Vitro Test ◽  
Chick Embryos ◽  
Amount Of Substance ◽  
Mammalian Embryos ◽  
Concentration Curves

Toxicokinetic studies are of key importance in both the design and the interpretation of developmental toxicity studies. The aim of this study was to determine concentrations of test substances within the chick embryo following the administration schedule recommended in the chick embryotoxicity screening test (CHEST). The concentration-time relationships were investigated by using four labelled substances with various physicochemical and embryo-toxic properties ([14C] sodium acetate, [14C] palmitic acid, [3H] Cortisol and [3H] cytosine arabinoside). These labelled chemicals were mixed with cold substances and singly administered at two dose levels to chick embryos on days 2, 3 and 4 of incubation. Extrachorial and subgerminal routes were used on day 2, and extrachorial and intra-amniotic applications were chosen on days 3 and 4. The concentration of labelled chemical present within the embryo was assessed at predetermined intervals by scintillation fluorimetry (from 6 minutes to 96 hours after administration), and used for estimating the concentration curves. Regardless of the substance, dose and application route, the concentration curves exhibited a characteristic pattern, reaching their peaks within the first 6 hours, and dropping down to near zero 48–96 hours after administration. The decrease followed the first order law, demonstrating that, within the CHEST system, the avian embryo does not act as a closed system. With regard to the total amount of substance entering the embryo, extrachorial administration appeared to be superior to subgerminal administration on day 2. Intra-amniotic administration was superior to extrachorial administration on days 3 and 4. These differences were most pronounced after administration of lipid-soluble palmitic acid. The concentrations within embryonic tissues were directly dose-dependent. After consideration of all these findings, we concluded that the CHEST system probably has closer similarity to the toxicokinetics of exposure of mammalian embryos (i.e. reaching a peak and then a gradual decline over time) than any other in vitro test of developmental toxicity, where the chemical is simply added to culture media. Several practical recommendations for improving the CHEST system were derived.

scholarly journals Coordination of intrinsic and extrinsic tongue muscles during spontaneous breathing in the rat

2004 ◽  
Vol 96 (2) ◽  
pp. 440-449 ◽  
Author(s):  
E. F. Bailey ◽  
R. F. Fregosi
Keyword(s):  
Muscle Activation ◽  
Respiratory Control ◽  
Esophageal Pressure ◽  
Emg Activity ◽  
Sensory Stimuli ◽  
Tongue Muscle ◽  
Tongue Muscles ◽  
Tongue Movements ◽  
And Function

The muscular-hydrostat model of tongue function proposes a constant interaction of extrinsic (external bony attachment, insertion into base of tongue) and intrinsic (origin and insertion within the tongue) tongue muscles in all tongue movements (Kier WM and Smith KK. Zool J Linn Soc 83: 207-324, 1985). Yet, research that examines the respiratory-related effects of tongue function in mammals continues to focus almost exclusively on the respiratory control and function of the extrinsic tongue protrusor muscle, the genioglossus muscle. The respiratory control and function of the intrinsic tongue muscles are unknown. Our purpose was to determine whether intrinsic tongue muscles have a respiration-related activity pattern and whether intrinsic tongue muscles are coactivated with extrinsic tongue muscles in response to respiratory-related sensory stimuli. Esophageal pressure and electromyographic (EMG) activity of an extrinsic tongue muscle (hyoglossus), an intrinsic tongue muscle (superior longitudinal), and an external intercostal muscle were studied in anesthetized, tracheotomized, spontaneously breathing rats. Mean inspiratory EMG activity was compared at five levels of inspired CO2. Intrinsic tongue muscles were often quiescent during eupnea but active during hypercapnia, whereas extrinsic tongue muscles were active in both eupnea and hypercapnia. During hypercapnia, the activities of the airway muscles were largely coincident, although the onset of extrinsic muscle activity generally preceded the onset of intrinsic muscle activation. Our findings provide evidence, in an in vivo rodent preparation, of respiratory modulation of motoneurons supplying intrinsic tongue muscles. Distinctions noted between intrinsic and extrinsic activities could be due to differences in motoneuron properties or the central, respiration-related control of each motoneuron population.

A time-lapse photographic study of chick embryos exposed to teratogenic doses of hypoxia

Development ◽  
1968 ◽  
Vol 19 (3) ◽  
pp. 347-362
Author(s):  
Casimer T. Grabowski ◽  
Robert E. Schroeder
Keyword(s):  
Oxygen Deficiency ◽  
Time Lapse ◽  
Abnormal Development ◽  
Chick Embryos ◽  
In Ovo ◽  
Culture Techniques ◽  
Mammalian Embryos ◽  
Major Period ◽  
The Many

Continuous, long-term observations of amniote embryos have always been difficult. Special culture techniques for young avian and mammalian embryos have been developed (New, 1967) and these have helped to visualize the early stages of development. But studies of normal and abnormal development during the major period of organogenesis have been made largely by tedious indirect methods, such as the examination of a series of embryos preserved at different time intervals. Transitory responses to toxic stimuli have been particularly difficult to detect in this manner. To observe the visible initial effects of teratogenic agents, a photographic time-lapse study of chick embryos in their natural, in ovo, state was initiated. This report compares the changes in normal and hypoxia-treated embryos during the third day of development. Of the many agents which produce abnormal development, oxygen deficiency is one of the better known, since (1) it is readily induced in the laboratory by a variety of means, and (2) it is generally considered to be a significantcause of spontaneously occurring anomalies (Rubsaamen, 1952; Ingalls, 1952).

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