| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
COMPLEX FUNCTION OF THE CENTRAL NERVOUS SYSTEM, SLEEP AND LOCOMOTION
1School of Health and Sport Sciences, Osaka University, Toyonaka City, Osaka 560-0043; 2Graduate School of Medicine and 5Faculty of Dentistry, Osaka University, Suita City, Osaka 565-0871; 3Faculty of Integrated Human Studies, Kyoto University, Kyoto City, Kyoto 606-8501; and 6National Center for Neurology and Psychiatry, Kodaira City, Tokyo 187-8551, Japan; and 4School of Dentistry, University of California, Los Angeles, California 90095-1527
Submitted 4 December 2003 ; accepted in final form 17 March 2004
Responses of electromyogram (EMG) in soleus muscle and both afferent and efferent neurograms at the fifth lumbar (L5) segmental level of spinal cord were investigated during acute and chronic unloading induced by hindlimb suspension and/or tenotomy in adult rats. The soleus EMG and afferent neurogram decreased 88 and 37%, respectively, relative to those at quadrupedal posture on the floor after acute hindlimb suspension that causes passive shortening of soleus due to ankle plantarflexion. However, the afferent neurogram (P < 0.05) and soleus EMG (P > 0.05) recorded on the floor increased after tenotomy of synergists. Furthermore, the afferent input was inhibited when the soleus EMG disappeared after tenotomy of soleus. The afferent neurogram and EMG of the soleus showed correlated responses to a variety of treatments, suggesting that the afferent neurogram recorded at the L5 segmental level reflects the neural input associated with the activity level of the soleus predominantly. The level of efferent neurogram decreased after acute hindlimb suspension but was not influenced significantly by tenotomy of synergists and/or soleus itself. The EMG and afferent neurograms remained low up to the 4th day but recovered to the preexperimental levels within 14 days, due to reorganization of sarcomere number and length, as well as the shortening of muscle fiber length and recovery of tension development. It is suggested that the levels of EMG and afferent neurogram associated with antigravity muscle are closely related to the tension development of the muscle.
soleus muscle; afferent and efferent neurogram; tension development; sarcomere remodeling
This article has been cited by other articles:
|
|
 |
|
  F. Kawano, Y. Takeno, N. Nakai, Y. Higo, M. Terada, T. Ohira, I. Nonaka, and Y. Ohira Essential role of satellite cells in the growth of rat soleus muscle fibers Am J Physiol Cell Physiol, August 1, 2008; 295(2): C458 - C467. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Kawano, Y. Matsuoka, Y. Oke, Y. Higo, M. Terada, X. D. Wang, N. Nakai, H. Fukuda, S. Imajoh-Ohmi, and Y. Ohira Role(s) of nucleoli and phosphorylation of ribosomal protein S6 and/or HSP27 in the regulation of muscle mass Am J Physiol Cell Physiol, July 1, 2007; 293(1): C35 - C44. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. D. Wang, F. Kawano, Y. Matsuoka, K. Fukunaga, M. Terada, M. Sudoh, A. Ishihara, and Y. Ohira Mechanical load-dependent regulation of satellite cell and fiber size in rat soleus muscle Am J Physiol Cell Physiol, April 1, 2006; 290(4): C981 - C989. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. W. Zderic and M. T. Hamilton Physical inactivity amplifies the sensitivity of skeletal muscle to the lipid-induced downregulation of lipoprotein lipase activity J Appl Physiol, January 1, 2006; 100(1): 249 - 257. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Riley, J. L. W. Bain, J. G. Romatowski, and R. H. Fitts Skeletal muscle fiber atrophy: altered thin filament density changes slow fiber force and shortening velocity Am J Physiol Cell Physiol, February 1, 2005; 288(2): C360 - C365. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
