Brittany N Krekeler1, Glen Leverson2, Nadine P Connor3. 1. Department of Communication Sciences and Disorders, Goodnight Hall, 1975 Willow Drive, Madison, WI, 53706, United States; Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, K4/7 Clinical Sciences Center, 600 Highland Avenue, Madison, WI 53792, United States. Electronic address: brittany.krekeler@wisc.edu. 2. Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, K4/7 Clinical Sciences Center, 600 Highland Avenue, Madison, WI 53792, United States. 3. Department of Communication Sciences and Disorders, Goodnight Hall, 1975 Willow Drive, Madison, WI, 53706, United States; Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, K4/7 Clinical Sciences Center, 600 Highland Avenue, Madison, WI 53792, United States.
Abstract
OBJECTIVE: This study sought to examin effects of age and tongue exercise on the posterior digastric (opener) and the temporalis (closer). We hypothesized 1) age would result in differing morphological (cross sectional area) and biochemical (myosin heavy chain isoform) components of these muscles; 2) tongue exercise would result in coactivation of these muscles inducing a decrease in age-related differences between age groups. DESIGN: Young adult (9 months) and old (32 months) Fischer 344 Brown Norway rats were randomized into a tongue exercise or control group. Post-training, posterior digastric and temporalis muscles were harvested and analyzed using: 1) Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) to assess percent myosin heavy chain (MyHC) content; 2) Immunohistochemical staining to determine cross sectional area (CSA). RESULTS: A larger proportion of slowly contracting MyHC isoforms in the posterior digastric and temporalis muscles were found in old. No significant main effects for age or exercise in fiber size were found in posterior digastric muscle. An interaction between age and exercise for temporalis cross sectional area indicated the old exercise group had smaller average cross sectional area than all other groups. CONCLUSIONS FINDINGS: suggest that: 1) Increasing age induces biochemical changes in muscles of the jaw, specifically showing an increase the proportion of slower contracting MyHC isoforms; 2) Increasing age and tongue exercise induce a reduction in muscle fiber cross sectional area in the temporalis muscle only. However, continued study of these cranial muscle systems is warranted to better understand these changes that occur with age and exercise.
OBJECTIVE: This study sought to examin effects of age and tongue exercise on the posterior digastric (opener) and the temporalis (closer). We hypothesized 1) age would result in differing morphological (cross sectional area) and biochemical (myosin heavy chain isoform) components of these muscles; 2) tongue exercise would result in coactivation of these muscles inducing a decrease in age-related differences between age groups. DESIGN: Young adult (9 months) and old (32 months) Fischer 344 Brown Norway rats were randomized into a tongue exercise or control group. Post-training, posterior digastric and temporalis muscles were harvested and analyzed using: 1) Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) to assess percent myosin heavy chain (MyHC) content; 2) Immunohistochemical staining to determine cross sectional area (CSA). RESULTS: A larger proportion of slowly contracting MyHC isoforms in the posterior digastric and temporalis muscles were found in old. No significant main effects for age or exercise in fiber size were found in posterior digastric muscle. An interaction between age and exercise for temporalis cross sectional area indicated the old exercise group had smaller average cross sectional area than all other groups. CONCLUSIONS FINDINGS: suggest that: 1) Increasing age induces biochemical changes in muscles of the jaw, specifically showing an increase the proportion of slower contracting MyHC isoforms; 2) Increasing age and tongue exercise induce a reduction in muscle fiber cross sectional area in the temporalis muscle only. However, continued study of these cranial muscle systems is warranted to better understand these changes that occur with age and exercise.
Authors: M A Nicosia; J A Hind; E B Roecker; M Carnes; J Doyle; G A Dengel; J Robbins Journal: J Gerontol A Biol Sci Med Sci Date: 2000-11 Impact factor: 6.053
Authors: Jacqueline R Kane; Michelle R Ciucci; Amber N Jacobs; Nathan Tews; John A Russell; Allison M Ahrens; Sean T Ma; Joshua M Britt; Lawrence K Cormack; Timothy Schallert Journal: J Commun Disord Date: 2011-04-30 Impact factor: 2.288
Authors: Nadine P Connor; John A Russell; Hao Wang; Michelle A Jackson; Laura Mann; Keith Kluender Journal: J Speech Lang Hear Res Date: 2008-08-22 Impact factor: 2.297
Authors: Mya Thein; William B Ershler; Andrew S Artz; Josephine Tecson; Bruce E Robinson; Gerald Rothstein; Alexander Liede; Ina Gylys-Colwell; Z John Lu; Sean Robbins Journal: Medicine (Baltimore) Date: 2009-03 Impact factor: 1.817
Authors: Erika R Murphy; Rebecca Thompson; Kate L Osman; Chandler Haxton; Margaret Brothers; Li Lee; Kristen Warncke; Catherine L Smith; Amy N Keilholz; Ali Hamad; Mojgan Golzy; Filiz Bunyak; Lixin Ma; Nicole L Nichols; Teresa E Lever Journal: Front Neurosci Date: 2022-06-30 Impact factor: 5.152