title: Cross-activation and detraining effects of tongue exercise in aged rats.
abstract: Voice and swallowing deficits can occur with aging. Tongue exercise paired with a swallow may be used to treat swallowing disorders, but may also benefit vocal function due to cross-system activation effects. It is unknown how exercise-based neuroplasticity contributes to behavior and maintenance following treatment. Eighty rats were used to examine behavioral parameters and changes in neurotrophins after tongue exercise paired with a swallow. Tongue forces and ultrasonic vocalizations were recorded before and after training/detraining in young and old rats. Tissue was analyzed for neurotrophin content. Results showed tongue exercise paired with a swallow was associated with increased tongue forces at all ages. Gains diminished after detraining in old rats. Age-related changes in vocalizations, neurotrophin 4 (NT4), and brain derived neurotrophic factor (BDNF) were found. Minimal cross-system activation effects were observed. Neuroplastic benefits were demonstrated with exercise in old rats through behavioral improvements and up-regulation of BDNF in the hypoglossal nucleus. Tongue exercise paired with a swallow should be developed, studied, and optimized in human clinical research to treat swallowing and voice disorders in elderly people.
authors.affiliation: Department of Communication Sciences and Disorders, Department of Surgery Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 53706, United States. Electronic address: ajschaser@gmail.com.
authors.forename: Allison J
authors.initials: AJ
authors.lastname: Schaser
authors.affiliation: Department of Communication Sciences and Disorders, Department of Surgery Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 53706, United States.
authors.forename: Michelle R
authors.initials: MR
authors.lastname: Ciucci
authors.affiliation: Department of Communication Sciences and Disorders, Department of Surgery Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin-Madison, 53706, United States.
authors.forename: Nadine P
authors.initials: NP
authors.lastname: Connor
mesh_terms: D000375:Aging / Q000502:physiology*; D000818:Animals; D001933:Brain Stem / Q000378:metabolism; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D003679:Deglutition / Q000502:physiology*; D005081:Exercise Therapy / Q000379:methods*; D007002:Hypoglossal Nerve / Q000378:metabolism; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism; D009473:Neuronal Plasticity / Q000502:physiology; D011897:Random Allocation; D011916:Rats, Inbred F344; D014059:Tongue / Q000502:physiology*; D016896:Treatment Outcome; D014465:Ultrasonics; D014828:Vocalization, Animal / Q000502:physiology
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; C073922:neurotrophin 4
keywords: Aging; Exercise dependent; Neuroplasticity; Neurotrophins; Swallowing; Tongue exercise; Voice