JSLHR
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Journal of Speech, Language, and Hearing Research Vol.51 818-827 August 2008. doi:10.1044/1092-4388(2008/059)
© American Speech-Language-Hearing Association
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow My Folders
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Connor, N. P.
Right arrow Articles by Leverson, G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Connor, N. P.
Right arrow Articles by Leverson, G.

Differences in Age-Related Alterations in Muscle Contraction Properties in Rat Tongue and Hindlimb

Nadine P. Connor
University of Wisconsin–Madison

Fumikazu Ota
Jikei University, Tokyo, Japan

Hiromi Nagai
Kitasato University, Kanagawa, Japan

John A. Russell
Glen Leverson
University of Wisconsin–Madison

Contact author: Nadine P. Connor, University of Wisconsin Clinical Science Center, Room K4/711, 600 Highland Avenue, Madison, WI 53792-7375. E-mail: connor{at}surgery.wisc.edu.

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 < .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.

KEY WORDS: aging, tongue, extensor digitorum longus, muscle contraction






HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
All ASHA Journals AJA AJSLP JSLHR LSHSS
Copyright © 2008 by the American Speech-Language-Hearing Association.