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Hoffmeister JD, Broadfoot CK, Schaen-Heacock NE, Lechner SA, Krasko MN, Nisbet AF, Russell J, Szot J, Glass TJ, Connor NP, Kelm-Nelson CA, Ciucci MR. Vocal and tongue exercise in early to mid-stage Parkinson disease using the Pink1-/- rat. Brain Res 2024; 1837:148958. [PMID: 38685371 PMCID: PMC11166513 DOI: 10.1016/j.brainres.2024.148958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 03/27/2024] [Accepted: 04/23/2024] [Indexed: 05/02/2024]
Abstract
Vocal and swallowing deficits are common in Parkinson disease (PD). Because these impairments are resistant to dopamine replacement therapies, vocal and lingual exercise are the primary treatment, but not all individuals respond to exercise and neural mechanisms of treatment response are unclear. To explore putative mechanisms, we used the progressive Pink1-/- rat model of early to mid-stage PD and employed vocal and lingual exercises at 6- and 10-months of age in male Pink1-/- and wild type (WT) rats. We hypothesized that vocal and lingual exercise would improve vocal and tongue use dynamics and increase serotonin (5HT) immunoreactivity in related brainstem nuclei. Rats were tested at baseline and after 8 weeks of exercise or sham exercise. At early-stage PD (6 months), vocal exercise resulted in increased call complexity, but did not change intensity, while at mid-stage (10 months), vocal exercise no longer influenced vocalization complexity. Lingual exercise increased tongue force generation and reduced relative optical density of 5HT in the hypoglossal nucleus at both time points. The effects of vocal and lingual exercise at these time points are less robust than in prodromal stages observed in previous work, suggesting that early exercise interventions may yield greater benefit. Future work targeting optimization of exercise at later time points may facilitate clinical translation.
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Affiliation(s)
- J D Hoffmeister
- University of Minnesota, Dept. of Otolaryngology, 420 Delaware Street SE, Minneapolis, MN 55422, USA; University of Wisconsin-Madison, Dept. of Communication Sciences and Disorders, 1975 Willow Drive, Madison, WI 53706, USA.
| | - C K Broadfoot
- University of South Alabama, Dept. of Speech Pathology and Audiology, 5721 USA Drive N, HAHN 1119, Mobile, AL 36688, USA; University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - N E Schaen-Heacock
- University of Wisconsin-Madison, Dept. of Communication Sciences and Disorders, 1975 Willow Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - S A Lechner
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - M N Krasko
- University of Wisconsin-Madison, Dept. of Communication Sciences and Disorders, 1975 Willow Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - A F Nisbet
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - J Russell
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - J Szot
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - T J Glass
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - N P Connor
- University of Wisconsin-Madison, Dept. of Communication Sciences and Disorders, 1975 Willow Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - C A Kelm-Nelson
- University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA.
| | - M R Ciucci
- University of Wisconsin-Madison, Dept. of Communication Sciences and Disorders, 1975 Willow Drive, Madison, WI 53706, USA; University of Wisconsin-Madison, Dept. of Surgery, Div. of Otolaryngology, 1300 University Avenue, 483 Medical Sciences Building, Madison, WI 53706, USA; University of Wisconsin-Madison, Neuroscience Training Program, 9531 WIMR II, 1111 Highland Ave., Madison, WI 53705, USA.
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2
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Fogarty MJ. Dendritic morphology of motor neurons and interneurons within the compact, semicompact, and loose formations of the rat nucleus ambiguus. Front Cell Neurosci 2024; 18:1409974. [PMID: 38933178 PMCID: PMC11199410 DOI: 10.3389/fncel.2024.1409974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 05/27/2024] [Indexed: 06/28/2024] Open
Abstract
Introduction Motor neurons (MNs) within the nucleus ambiguus innervate the skeletal muscles of the larynx, pharynx, and oesophagus. These muscles are activated during vocalisation and swallowing and must be coordinated with several respiratory and other behaviours. Despite many studies evaluating the projections and orientation of MNs within the nucleus ambiguus, there is no quantitative information regarding the dendritic arbours of MNs residing in the compact, and semicompact/loose formations of the nucleus ambiguus.. Methods In female and male Fischer 344 rats, we evaluated MN number using Nissl staining, and MN and non-MN dendritic morphology using Golgi-Cox impregnation Brightfield imaging of transverse Nissl sections (15 μm) were taken to stereologically assess the number of nucleus ambiguus MNs within the compact and semicompact/loose formations. Pseudo-confocal imaging of Golgi-impregnated neurons within the nucleus ambiguus (sectioned transversely at 180 μm) was traced in 3D to determine dendritic arbourisation. Results We found a greater abundance of MNs within the compact than the semicompact/loose formations. Dendritic lengths, complexity, and convex hull surface areas were greatest in MNs of the semicompact/loose formation, with compact formation MNs being smaller. MNs from both regions were larger than non-MNs reconstructed within the nucleus ambiguus. Conclusion Adding HBLS to the diet could be a potentially effective strategy to improve horses' health.
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Affiliation(s)
- Matthew J. Fogarty
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
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Broadfoot CK, Hoffmeister JD, Lechner SA, Krasko MN, Lambert E, Russell JA, Szot JC, Glass TJ, Connor NP, Kelm-Nelson CA, Ciucci MR. Tongue and laryngeal exercises improve tongue strength and vocal function outcomes in a Pink1-/- rat model of early Parkinson disease. Behav Brain Res 2024; 460:114754. [PMID: 37981125 PMCID: PMC10872343 DOI: 10.1016/j.bbr.2023.114754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 11/03/2023] [Accepted: 11/06/2023] [Indexed: 11/21/2023]
Abstract
Parkinson disease (PD) causes voice and swallow dysfunction even in early stages of the disease. Treatment of this dysfunction is limited, and the neuropathology underlying this dysfunction is poorly defined. Targeted exercise provides the greatest benefit for offsetting voice and swallow dysfunction, and previous data suggest the hypoglossal nucleus and noradrenergic-locus coeruleus (LC) may be involved in its early pathology. To investigate relationships between targeted exercise and neuropathology of voice and swallow dysfunction, we implemented a combined exercise paradigm that included tongue force and vocalization exercises early in the Pink1-/- rat model. We tested the hypotheses that (1) tongue and vocal exercise improves tongue force and timing behaviors and vocalization outcomes, and (2) exercise increases optical density of serotonin (5-HT) in the hypoglossal nucleus, and tyrosine hydroxylase immunoreactive (Th-ir) cell counts in the LC. At two months of age Pink1-/- rats were randomized to exercise or non-exercise treatment. Age-matched wildtype (WT) control rats were assigned to non-exercise treatment. Tongue force and timing behaviors and ultrasonic vocalizations were measured at baseline (two months) and final (four months) timepoints. Optical density of 5-HT in the hypoglossal nucleus and TH-ir cell counts in the LC were obtained. Pink1-/- rats produced greater tongue forces, faster tongue contraction, and higher-intensity vocalization following exercise. There were no differences in LC TH-ir. The non-exercised Pink1-/- group had reduced density of 5-HT in the hypoglossal nucleus compared to the WT control group. The changes to tongue function and vocalization after targeted exercise suggests exercise intervention may be beneficial in early PD.
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Affiliation(s)
- Courtney K Broadfoot
- University of South Alabama, Department of Speech Pathology & Audiology, 36688, USA.
| | | | - Sarah A Lechner
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - Maryann N Krasko
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA; University of Wisconsin-Madison, Department of Communication Sciences and Disorders, 53706, USA
| | - Emily Lambert
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - John A Russell
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - John C Szot
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - Tiffany J Glass
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - Nadine P Connor
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA; University of Wisconsin-Madison, Department of Communication Sciences and Disorders, 53706, USA; University of Wisconsin-Madison, Neuroscience Training Program, 53706, USA
| | - Cynthia A Kelm-Nelson
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA
| | - Michelle R Ciucci
- University of Wisconsin-Madison Department of Surgery, Division of Otolaryngology-Head & Neck Surgery, 53706, USA; University of Wisconsin-Madison, Department of Communication Sciences and Disorders, 53706, USA; University of Wisconsin-Madison, Neuroscience Training Program, 53706, USA
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Szynkiewicz SH, Drulia T, Griffin L, Mulheren R, Murray KL, Lee T, Kamarunas E. Flexibility for Intensity Dosing in Lingual Resistance Exercises: A Large Randomized Clinical Trial in Typically Aging Adults as Proof of Principle. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2023; 32:3021-3035. [PMID: 37850842 DOI: 10.1044/2023_ajslp-23-00113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2023]
Abstract
OBJECTIVE The objective of this study was to determine the effect of intensity dosing during tongue exercise on tongue pressure generation, adherence, and perceived effort. DESIGN This was a five-site, prospective, randomized clinical trial. Outcome measures were obtained across multiple baselines, biweekly during exercise, and 4-weeks post-intervention. SETTING The general community at each study site. PARTICIPANTS Typically aging adults between 55-82 years of age with no history of neurological or swallowing disorders. Eighty-four volunteers completed the study. INTERVENTIONS Participants were randomly assigned to one of four exercise groups: (a) maximum intensity/no biofeedback, (b) progressive intensity/no biofeedback, (c) maximum intensity/biofeedback, and (d) progressive intensity/biofeedback. Half of the participants completed a maintenance exercise program. OUTCOME MEASURES Maximum isometric pressure (MIP), regular effort saliva swallow pressure, adherence, and the Borg Rating of Perceived Exertion Scale. RESULTS All exercise protocols were efficacious for gains in MIP (large effect sizes; Cohen's d). Group 3 made gains in regular effort saliva swallow pressure (medium effect size). There was a significant change in perceived exertion for regular effort saliva swallow pressure at 8 weeks. Tongue pressure gains were maintained at 1 month, regardless of maintenance group status. Mean adherence across groups was high. CONCLUSIONS All groups improved pressure generation. Intensity dosing differences did not affect strength gains, adherence, or detraining. Regular effort saliva swallow pressure may be most responsive to maximum intensity with biofeedback. The findings suggest flexibility in approach to tongue exercise protocols. Tongue muscles may differ from limb muscles in terms of dose response and neuroplasticity principles.
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Affiliation(s)
- Sarah H Szynkiewicz
- Department of Communication Sciences and Disorders, Samford University, Birmingham, AL
| | - Teresa Drulia
- Davies School of Communication Sciences and Disorders, Texas Christian University, Fort Worth
| | - Lindsay Griffin
- Department of Communication Sciences and Disorders, Emerson College, Boston, MA
| | - Rachel Mulheren
- Department of Psychological Sciences, Case Western Reserve University, Cleveland, OH
| | - Kelsey L Murray
- Department of Communication Sciences and Disorders, James Madison University, Harrisonburg, VA
| | - Theresa Lee
- Department of Psychological Sciences, Case Western Reserve University, Cleveland, OH
| | - Erin Kamarunas
- Department of Communication Sciences and Disorders, James Madison University, Harrisonburg, VA
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Krasko MN, Rudisch DM, Burdick RJ, Schaen-Heacock NE, Broadfoot CK, Nisbet AF, Rogus-Pulia N, Ciucci MR. Dysphagia in Parkinson Disease: Part II-Current Treatment Options and Insights from Animal Research. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2023; 11:188-198. [PMID: 39301152 PMCID: PMC11411792 DOI: 10.1007/s40141-023-00393-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2023] [Indexed: 09/22/2024]
Abstract
Purpose of Review Dysphagia is highly prevalent in Parkinson disease (PD) but is not typically identified nor treated until later in the disease process. This review summarizes current pharmacological, surgical, and behavioral treatments for PD-associated dysphagia and contributions from translational animal research. Recent Findings Swallowing is a complex physiologic process controlled by multiple brain regions and neurotransmitter systems. As such, interventions that target nigrostriatal dopamine dysfunction have limited or detrimental effects on swallowing outcomes. Behavioral interventions can help target PD-associated dysphagia in mid-to-late stages. Animal research is necessary to refine treatments and useful in studying prodromal dysphagia. Summary Dysphagia is an early, common, and debilitating sign of PD. Current pharmacological and surgical interventions are not effective in ameliorating swallowing dysfunction; behavioral intervention remains the most effective approach for dysphagia treatment. Animal research has advanced our understanding of mechanisms underlying PD and PD-associated dysphagia, and continues to show translational promise for the study of dysphagia treatment options.
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Affiliation(s)
- Maryann N Krasko
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 1300 University Ave, Madison, WI 53706, USA
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, 1975 Willow Drive, Madison, WI 53706, USA
| | - Denis Michael Rudisch
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 1300 University Ave, Madison, WI 53706, USA
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, 1975 Willow Drive, Madison, WI 53706, USA
| | - Ryan J Burdick
- Department of Medicine, Division of Geriatrics and Gerontology, School of Medicine and Public Health, University of Wisconsin-Madison, 1685 Highland Avenue, Madison, WI 53705, USA
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA
| | - Nicole E Schaen-Heacock
- Department of Medicine, Division of Geriatrics and Gerontology, School of Medicine and Public Health, University of Wisconsin-Madison, 1685 Highland Avenue, Madison, WI 53705, USA
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA
| | - Courtney K Broadfoot
- Department of Medicine, Division of Geriatrics and Gerontology, School of Medicine and Public Health, University of Wisconsin-Madison, 1685 Highland Avenue, Madison, WI 53705, USA
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA
| | - Alex F Nisbet
- Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Blvd, Philadelphia, PA 19104, USA
| | - Nicole Rogus-Pulia
- Department of Medicine, Division of Geriatrics and Gerontology, School of Medicine and Public Health, University of Wisconsin-Madison, 1685 Highland Avenue, Madison, WI 53705, USA
- Geriatric Research Education and Clinical Center, William S. Middleton Memorial Veterans Hospital, 2500 Overlook Terrace, Madison, WI 53705, USA
| | - Michelle R Ciucci
- Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 1300 University Ave, Madison, WI 53706, USA
- Department of Communication Sciences and Disorders, University of Wisconsin-Madison, 1975 Willow Drive, Madison, WI 53706, USA
- Neuroscience Training Program, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI 53705, USA
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Koecklin KHU, Kato C, Abe Y, Yabushita T, Kokai S, Ono T. Histological and contractile changes in the genioglossus muscle after nasal obstruction in growing rats. Sci Rep 2023; 13:6245. [PMID: 37069178 PMCID: PMC10110532 DOI: 10.1038/s41598-023-32921-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 04/04/2023] [Indexed: 04/19/2023] Open
Abstract
The aim of the study was to address the genioglossus muscle physiological and histological changes after unilateral nasal obstruction in growing rats. Fifty-four 6-day-old male Wistar albino rats were randomly divided into control (n = 27) and experimental (n = 27) groups. Unilateral nasal obstruction was performed at 8 days old. Contractile properties of the genioglossus whole muscle were measured at 5-, 7- and 9-week-old, including the twitch and tetanic forces, contraction time, half-decay time, and fatigue index. The histological characteristics of the genioglossus were also evaluated at 5-, 7- and 9-week-old, analyzing the myosin heavy chain composition of the slow, fast, IIa and IIb muscle fiber type, by measuring the number, rate, diameter and cross-sectional area. The maximal twitch force, and tetanic force at 60 Hz and 80 Hz force was significantly increased at all ages after nasal obstruction. The fatigue index was decreased at 5 weeks-old after nasal obstruction. The diameter and cross-sectional area of the fast, IIa and IIb muscle fiber types were increased at 7 and 9 weeks after nasal obstruction, while only the diameter of IIa type and cross-sectional area of IIb type were increased at 5 weeks-old after nasal obstruction. Nasal obstruction during growth affects the whole genioglossus muscle contractile properties and histological characteristics, increasing its force, the diameter and area of its muscle fibers. These changes in the genioglossus muscle may affect the normal growth, development and function of the craniofacial complex.
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Affiliation(s)
| | - Chiho Kato
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Yasunori Abe
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | | | - Satoshi Kokai
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
| | - Takashi Ono
- Department of Orthodontic Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan
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Bioenergetic Evaluation of Muscle Fatigue in Murine Tongue. Dysphagia 2022:10.1007/s00455-022-10537-y. [DOI: 10.1007/s00455-022-10537-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 10/26/2022] [Indexed: 11/21/2022]
Abstract
AbstractMuscle fatigue is the diminution of force required for a particular action over time. Fatigue may be particularly pronounced in aging muscles, including those used for swallowing actions. Because risk for swallowing impairment (dysphagia) increases with aging, the contribution of muscle fatigue to age-related dysphagia is an emerging area of interest. The use of animal models, such as mice and rats (murine models) allows experimental paradigms for studying the relationship between muscle fatigue and swallowing function with a high degree of biological precision that is not possible in human studies. The goal of this article is to review basic experimental approaches to the study of murine tongue muscle fatigue related to dysphagia. Traditionally, murine muscle fatigue has been studied in limb muscles through direct muscle stimulation and behavioral exercise paradigms. As such, physiological and bioenergetic markers of muscle fatigue that have been validated in limb muscles may be applicable in studies of cranial muscle fatigue with appropriate modifications to account for differences in muscle architecture, innervation ratio, and skeletal support. Murine exercise paradigms may be used to elicit acute fatigue in tongue muscles, thereby enabling study of putative muscular adaptations. Using these approaches, hypotheses can be developed and tested in mice and rats to allow for future focused studies in human subjects geared toward developing and optimizing treatments for age-related dysphagia.
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8
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Murphy ER, Thompson R, Osman KL, Haxton C, Brothers M, Lee L, Warncke K, Smith CL, Keilholz AN, Hamad A, Golzy M, Bunyak F, Ma L, Nichols NL, Lever TE. A Strength Endurance Exercise Paradigm Mitigates Deficits in Hypoglossal-Tongue Axis Function, Strength, and Structure in a Rodent Model of Hypoglossal Motor Neuron Degeneration. Front Neurosci 2022; 16:869592. [PMID: 35844238 PMCID: PMC9279620 DOI: 10.3389/fnins.2022.869592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/23/2022] [Indexed: 11/18/2022] Open
Abstract
The tongue plays a crucial role in the swallowing process, and impairment can lead to dysphagia, particularly in motor neuron diseases (MNDs) resulting in hypoglossal-tongue axis degeneration (e.g., amyotrophic lateral sclerosis and progressive bulbar palsy). This study utilized our previously established inducible rodent model of dysphagia due to targeted degeneration of the hypoglossal-tongue axis. This model was created by injecting cholera toxin B conjugated to saporin (CTB-SAP) into the genioglossus muscle of the tongue base for retrograde transport to the hypoglossal (XII) nucleus via the hypoglossal nerve, which provides the sole motor control of the tongue. Our goal was to investigate the effect of high-repetition/low-resistance tongue exercise on tongue function, strength, and structure in four groups of male rats: (1) control + sham exercise (n = 13); (2) control + exercise (n = 10); (3) CTB-SAP + sham exercise (n = 13); and (4) CTB-SAP + exercise (n = 12). For each group, a custom spout with adjustable lick force requirement for fluid access was placed in the home cage overnight on days 4 and 6 post-tongue injection. For the two sham exercise groups, the lick force requirement was negligible. For the two exercise groups, the lick force requirement was set to ∼40% greater than the maximum voluntary lick force for individual rats. Following exercise exposure, we evaluated the effect on hypoglossal-tongue axis function (via videofluoroscopy), strength (via force-lickometer), and structure [via Magnetic Resonance Imaging (MRI) of the brainstem and tongue in a subset of rats]. Results showed that sham-exercised CTB-SAP rats had significant deficits in lick rate, swallow timing, and lick force. In exercised CTB-SAP rats, lick rate and lick force were preserved; however, swallow timing deficits persisted. MRI revealed corresponding degenerative changes in the hypoglossal-tongue axis that were mitigated by tongue exercise. These collective findings suggest that high-repetition/low-resistance tongue exercise in our model is a safe and effective treatment to prevent/diminish signs of hypoglossal-tongue axis degeneration. The next step is to leverage our rat model to optimize exercise dosing parameters and investigate corresponding treatment mechanisms of action for future translation to MND clinical trials.
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Affiliation(s)
- Erika R. Murphy
- Department of Speech, Language and Hearing Sciences, School of Health Professions, University of Missouri, Columbia, MO, United States
| | - Rebecca Thompson
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO, United States
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Kate L. Osman
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Chandler Haxton
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Margaret Brothers
- Department of Speech, Language and Hearing Sciences, School of Health Professions, University of Missouri, Columbia, MO, United States
| | - Li Lee
- Department of Radiology, School of Medicine, University of Missouri, Columbia, MO, United States
- Research Division, Biomolecular Imaging Center, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO, United States
| | - Kristen Warncke
- Department of Radiology, School of Medicine, University of Missouri, Columbia, MO, United States
- Research Division, Biomolecular Imaging Center, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO, United States
| | - Catherine L. Smith
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Amy N. Keilholz
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Ali Hamad
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, United States
| | - Mojgan Golzy
- Biostatistics Unit, Department of Family and Community Medicine, University of Missouri, Columbia, MO, United States
| | - Filiz Bunyak
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO, United States
| | - Lixin Ma
- Department of Radiology, School of Medicine, University of Missouri, Columbia, MO, United States
- Research Division, Biomolecular Imaging Center, Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO, United States
| | - Nicole L. Nichols
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, United States
- *Correspondence: Nicole L. Nichols,
| | - Teresa E. Lever
- Department of Speech, Language and Hearing Sciences, School of Health Professions, University of Missouri, Columbia, MO, United States
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Missouri, Columbia, MO, United States
- Department of Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
- Teresa E. Lever,
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9
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Assays of Tongue Force, Timing, and Dynamics in Rat and Mouse Models. Brain Res Bull 2022; 185:49-55. [PMID: 35469932 PMCID: PMC10187612 DOI: 10.1016/j.brainresbull.2022.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/13/2022] [Accepted: 04/20/2022] [Indexed: 12/18/2022]
Abstract
Communication and swallowing are highly complex sensorimotor events that are tightly linked to respiration and vital to health and well-being. The tongue is a complex organ, often described as a muscular hydrostat, that is crucial for maintaining airway patency, preparing and safely transporting food/liquid, and rapidly changing position and shape for speech. As with any complex behavior, tongue function can be compromised with aging, diseases/conditions, trauma, or as a pharmacologic side effect. As such, modeling lingual function and dysfunction for basic and translational research is paramount; understanding how the nervous system controls tongue function for complex behavior is foundational to this work. Non-invasive access to tongue tissues and kinematics during awake behavior has been historically challenging, creating a critical need to measure tongue function in model systems. Germane to this field of study are the instruments and assays of licking/lapping and drinking, including tongue force and timing measures, many of which were designed or modified by Dr. Stephen C. Fowler. The focus of this paper is to review some of the important contributions of measuring tongue behaviors in awake rats and mice and how these have been modified by other researchers to advance translational science.
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Glass TJ, Figueroa JE, Russell JA, Krekeler BN, Connor NP. Progressive Protrusive Tongue Exercise Does Not Alter Aging Effects in Retrusive Tongue Muscles. Front Physiol 2021; 12:740876. [PMID: 34744782 PMCID: PMC8567011 DOI: 10.3389/fphys.2021.740876] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/27/2021] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Tiffany J Glass
- Department of Surgery-Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | | | - John A Russell
- Department of Surgery-Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States
| | - Brittany N Krekeler
- Department of Surgery-Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States.,Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL, United States
| | - Nadine P Connor
- Department of Surgery-Otolaryngology, University of Wisconsin-Madison, Madison, WI, United States.,Department of Communication Sciences and Disorders, University of Wisconsin-Madison, Madison, WI, United States
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11
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Bordoni B, Escher AR. A Missing Voice: The Lingual Complex and Osteopathic Manual Medicine in the Context of Five Osteopathic Models. Cureus 2021; 13:e18658. [PMID: 34659928 PMCID: PMC8503936 DOI: 10.7759/cureus.18658] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2021] [Indexed: 12/19/2022] Open
Abstract
The five osteopathic models recognized by the American Association of Colleges of Osteopathic Medicine guide clinicians in the evaluation and therapeutic choice which must be the most appropriate concerning the patient's needs. Skeletal muscles represent an important interpretation, such as screening and treatment, on which these models are based. A muscle district that is not considered by the usual osteopathic practice is the tongue. The lingual complex has numerous functions, both local and systemic; it can adapt negatively in the presence of pathology, just as it can influence the body system in a non-physiological manner if it is a source of dysfunctions. This paper, the first of its kind in the panorama of scientific literature, briefly reviews the anatomy and neurophysiology of the tongue, trying to highlight the logic and the need to insert this muscle in the context of the five osteopathic models. The clinician's goal is to restore the patient's homeostasis, and we believe that this task is more concrete if the patient is approached after understanding all the contractile districts, including the tongue.
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Affiliation(s)
- Bruno Bordoni
- Physical Medicine and Rehabilitation, Don Carlo Gnocchi Foundation, Milan, ITA
| | - Allan R Escher
- Anesthesiology/Pain Medicine, H. Lee Moffitt Cancer Center and Research Institute, Tampa, USA
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12
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Fogarty MJ, Sieck GC. Tongue muscle contractile, fatigue, and fiber type properties in rats. J Appl Physiol (1985) 2021; 131:1043-1055. [PMID: 34323593 DOI: 10.1152/japplphysiol.00329.2021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The intrinsic and extrinsic tongue muscles manipulate the position and shape of the tongue and are activated during many oral and respiratory behaviors. In the present study, in 6-mo-old Fischer 344 rats, we examined mechanical and fatigue properties of tongue muscles in relation to their fiber type composition. In an ex vivo preparation, isometric force and fatigue was assessed by direct muscle stimulation. Tongue muscles were frozen in melting isopentane and transverse sections cut at 10 µm. In hematoxylin-eosin (H&E)-stained muscle sections, the relative fractions of muscle versus extracellular matrix were determined. Muscle fibers were classified as type I, IIa and IIx, and/or IIb based on immunoreactivity to specific myosin heavy chain isoform antibodies. Cross-sectional areas (CSAs) and proportions of different fiber types were used to calculate their relative contribution to total muscle CSAs. We found that the superior and inferior longitudinal intrinsic muscles (4.4 N/cm2) and genioglossus muscle (3.0 N/cm2) generated the greatest maximum isometric force compared with the transversalis muscle (0.9 N/cm2). The longitudinal muscles and the transversalis muscle displayed greater fatigue during repetitive stimulation consistent with the greater relative contribution of type IIx and/or IIb fibers. By contrast, the genioglossus, comprising a higher proportion of type I and IIa fibers, was more fatigue resistant. This study advances our understanding of the force, fatigue, and fiber type-specific properties of individual tongue musculature. The assessments and approach provide a readily accessible muscular readout for scenarios where motor control dysfunction or tongue weakness is evident.NEW & NOTEWORTHY For the individual tongue muscles, relatively little quantification of uniaxial force, fatigue, and fiber type-specific properties has been documented. Here, we assessed uniaxial-specific force generation, fatigability, and muscle fiber type-specific properties in the superior and inferior longitudinal muscles, the transversalis, and the genioglossus in Fischer 344 rats. The longitudinal muscles produced the greatest isometric tetanic-specific forces. The genioglossus was more fatigue resistant and comprised higher proportions of I and IIa fibers.
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Affiliation(s)
- Matthew J Fogarty
- Department of Physiology and Biomedical Engineering, grid.66875.3aMayo Clinic, Rochester, Minnesota
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, grid.66875.3aMayo Clinic, Rochester, Minnesota
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13
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Huang H, Li W, Jin H, Zhang L, Wei Z, Wang W. Tongue Strength Training Increases Daytime Upper Airway Stability in Rats. Nat Sci Sleep 2021; 13:1653-1661. [PMID: 34588832 PMCID: PMC8473720 DOI: 10.2147/nss.s328214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 09/07/2021] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Tongue strength training (TST) has been shown to decrease the apnea-hypopnea index in some patients with obstructive sleep apnea (OSA). However, whether TST modulates the central regulation of genioglossus and influences the stability of the upper airway remains unknown. The purpose of this study was to dynamically assess the effect of TST on the upper airway. METHODS Sixteen adult male Sprague-Dawley rats were studied to explore the mechanism of TST improving the upper airway function. The rats were randomly assigned to the normal control (NC) and TST groups. The TST group underwent 8-week progressive resistance tongue exercise training. Transcranial magnetic stimulation (TMS) responses and EMG activities were consistently recorded for 2 h on days 0, 14, 28, and 56 of the experiments in both groups. Theoretical critical pressure (Pcrit) value was measured on days 0, 14, 28, and 56. RESULTS The TST group showed shorter TMS latency and higher genioglossus EMG activity, which lasted from 5 min to 80 min after training on day 56 of training, than the NC group. The TST group showed significantly lower theoretical Pcrit values on days 28 and 56 of training than the NC group (-4.07±0.92 vs -3.12±0.77 cmH2O, P< 0.05, -4.66±0.74 vs -3.07±0.38 cmH2O, P< 0.01). CONCLUSION This study revealed that an 8-week TST could gradually and transiently increase corticomotor excitability of genioglossus, elevate the genioglossus EMG activity, and ultimately enhance the stability of the upper airway during daytime. Moreover, improved neuromuscular excitability occurred prior to the enhanced upper airway stability. These findings provide a theoretical foundation for TST as a promising treatment for OSA patients.
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Affiliation(s)
- Hong Huang
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Wenyang Li
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Hongyu Jin
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Lei Zhang
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Zhijing Wei
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
| | - Wei Wang
- Institute of Respiratory and Critical Care, The First Hospital of China Medical University, Shenyang, People's Republic of China
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