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ERIC Number: EJ803602
Record Type: Journal
Publication Date: 2008-Aug-1
Pages: 10
Abstractor: As Provided
Reference Count: 0
ISBN: N/A
ISSN: ISSN-1092-4388
Differences in Age-Related Alterations in Muscle Contraction Properties in Rat Tongue and Hindlimb
Connor, Nadine P.; Ota, Fumikazu; Nagai, Hiromi; Russell, John A.; Leverson, Glen
Journal of Speech, Language, and Hearing Research, v51 n4 p818-827 Aug 2008
Purpose: Because of differences in muscle architecture and biomechanics, the purpose of this study was to determine whether muscle contractile properties of rat hindlimb and tongue were differentially affected by aging. Method: Deep peroneal and hypoglossal nerves were stimulated in 6 young and 7 old Fischer 344-Brown Norway rats to allow recording of muscle contractile properties of tongue and extensor digitorum longus (EDL) muscle in the hindlimb. In the same animals, the following measurements were made: (a) twitch contraction time (CT; in milliseconds), (b) half decay time (HDT; in milliseconds), (c) maximum twitch force (in grams), (d) tetanic force, and (e) fatigue index determined from repetitive stimulation of the muscles. Results: No significant differences were observed in young versus old groups in retrusive tongue forces, whereas a significant (p less than 0.05) decrement in EDL tetanic forces was found in old rats. Slower CT in old rats was observed only in the tongue. Old and young groups were not significantly different in fatigue index or HDT for tongue or EDL. Conclusions: Old animals generated equivalent maximum tongue forces with stimulation, but they were slower in achieving these forces than young animals. Limb and cranial muscles were not affected equally by aging. As such, information derived from limb muscle studies may not easily generalize to the cranial motor system.
American Speech-Language-Hearing Association (ASHA). 10801 Rockville Pike, Rockville, MD 20852. Tel: 800-638-8255; Fax: 301-571-0457; e-mail: subscribe@asha.org; Web site: http://www.asha.org/about/publications/journal-abstracts/jslhr/
Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A