ERIC Number: EJ983916
Record Type: Journal
Publication Date: 2012-Jun
Abstractor: As Provided
Reference Count: 0
The Effect of Tongue Exercise on Serotonergic Input to the Hypoglossal Nucleus in Young and Old Rats
Behan, Mary; Moeser, Adam E.; Thomas, Cathy F.; Russell, John A.; Wang, Hao; Leverson, Glen E.; Connor, Nadine P.
Journal of Speech, Language, and Hearing Research, v55 n3 p919-929 Jun 2012
Purpose: Breathing and swallowing problems affect elderly people and may be related to age-associated tongue dysfunction. Hypoglossal motoneurons that innervate the tongue receive a robust, excitatory serotonergic (5HT) input and may be affected by aging. We used a rat model of aging and progressive resistance tongue exercise to determine whether age-related alterations in 5HT inputs to the hypoglossal nucleus can be modified. We hypothesized that tongue forces would increase with exercise, 5HT input to the tongue would decrease with age, and tongue exercise would augment 5HT input to the hypoglossal nucleus. Method: Young (9-10 months), middle-aged (24-25 months), and old (32-33 months) male F344/BN rats received tongue exercise for 8 weeks. Immunoreactivity for 5HT was measured in digital images of sections through the hypoglossal nucleus using ImageJ software. Results: Tongue exercise resulted in increased maximum tongue forces at all ages. There was a statistically significant increase in 5HT immunoreactivity in the hypoglossal nucleus in exercised, young rats but only in the caudal third of the nucleus and primarily in the ventral half. Conclusion: Specificity found in serotonergic input following exercise may reflect the topographic organization of motoneurons in the hypoglossal nucleus and the tongue muscles engaged in the exercise paradigm.
Descriptors: Animals, Experiments, Diseases, Hypothesis Testing, Age Differences, Aging (Individuals), Exercise, Exercise Physiology, Human Body, Older Adults, Geriatrics, Statistical Analysis
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A