| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Physiological Science, University of California, Los Angeles, Los Angeles, CA, USA
2 Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
3 Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
4 Physiological Science, University of California, Los Angeles, Los Angeles, CA, USA; Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, USA
* To whom correspondence should be addressed. E-mail: jphyatt{at}ucla.edu.
Electrical activity is thought to be the primary neural stimulus regulating muscle mass, expression of Myogenic Regulatory Factor (MRF) genes, and cellular activity within skeletal muscle. However, the relative contribution of neural influences that are activity-dependent and -independent in modulating these characteristics is unclear. Comparisons of denervation (no neural influence) and spinal cord isolation (SI, neural influence with minimal activity) after 3, 14, and 28 days of treatment were used to demonstrate whether there are neural influences on muscle that are activity independent. Furthermore, the effects of these manipulations were compared for a fast ankle extensor (medial gastrocnemius, MG) and a fast ankle flexor (tibialis anterior, TA). The mass of both muscles plateaued at ~60% of control 2 weeks post-SI, whereas both muscles progressively atrophied to <25% of initial mass at this same time point after denervation. A rapid increase in Myogenin and, to a lesser extent MyoD, RNAs and proteins was observed in denervated and SI muscles: at the later time points, these MRFs remained elevated in denervated, but not SI muscles. This widespread neural activity-independent influence on MyoD and Myogenin expression was observed in both myonuclei and satellite cells and was not specific for fast or slow fiber phenotypes. Mitotic activity of satellite and connective tissue cells also was consistently lower in SI than denervated muscles. These results demonstrate a neural effect independent of electrical activity that 1) helps preserve muscle mass, 2) regulates muscle-specific genes, and 3) potentially spares the satellite cell pool in inactive muscles.
This article has been cited by other articles:
|
|
 |
|
  M. Velders, K. Legerlotz, S. J. Falconer, N. S. Stott, C. D. McMahon, and H. K. Smith Effect of botulinum toxin A-induced paralysis and exercise training on mechanosensing and signalling gene expression in juvenile rat gastrocnemius muscle Exp Physiol, December 1, 2008; 93(12): 1273 - 1283. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. C. Yohn, G. B. Miles, V. F. Rafuse, and R. M. Brownstone Transplanted Mouse Embryonic Stem-Cell-Derived Motoneurons Form Functional Motor Units and Reduce Muscle Atrophy J. Neurosci., November 19, 2008; 28(47): 12409 - 12418. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Szabo, F. Wuytack, and E. Zador The Effect of Passive Movement on Denervated Soleus Highlights a Differential Nerve Control on SERCA and MyHC Isoforms J. Histochem. Cytochem., November 1, 2008; 56(11): 1013 - 1022. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 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]
|
|
|
|
 |
|
 D. C. Button, J. M. Kalmar, K. Gardiner, T. Marqueste, H. Zhong, R. R. Roy, V. R. Edgerton, and P. F. Gardiner Does elimination of afferent input modify the changes in rat motoneurone properties that occur following chronic spinal cord transection? J. Physiol., January 15, 2008; 586(2): 529 - 544. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. R. Adams, F. Haddad, P. W. Bodell, P. D. Tran, and K. M. Baldwin Combined isometric, concentric, and eccentric resistance exercise prevents unloading-induced muscle atrophy in rats J Appl Physiol, November 1, 2007; 103(5): 1644 - 1654. [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]
|
|
|
|
|
|
J. G. Tidball and M. Wehling-Henricks Macrophages promote muscle membrane repair and muscle fibre growth and regeneration during modified muscle loading in mice in vivo J. Physiol., January 1, 2007; 578(1): 327 - 336. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Raue, D. Slivka, B. Jemiolo, C. Hollon, and S. Trappe Myogenic gene expression at rest and after a bout of resistance exercise in young (18-30 yr) and old (80-89 yr) women J Appl Physiol, July 1, 2006; 101(1): 53 - 59. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. Bruusgaard, K. Liestol, and K. Gundersen Distribution of myonuclei and microtubules in live muscle fibers of young, middle-aged, and old mice J Appl Physiol, June 1, 2006; 100(6): 2024 - 2030. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Raffaello, P. Laveder, C. Romualdi, C. Bean, L. Toniolo, E. Germinario, A. Megighian, D. Danieli-Betto, C. Reggiani, and G. Lanfranchi Denervation in murine fast-twitch muscle: short-term physiological changes and temporal expression profiling Physiol Genomics, March 13, 2006; 25(1): 60 - 74. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Vissing, J. L. Andersen, S. D. R. Harridge, C. Sandri, A. Hartkopp, M. Kjaer, and P. Schjerling Gene expression of myogenic factors and phenotype-specific markers in electrically stimulated muscle of paraplegics J Appl Physiol, July 1, 2005; 99(1): 164 - 172. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. M. Giger, F. Haddad, A. X. Qin, M. Zeng, and K. M. Baldwin Effect of unloading on type I myosin heavy chain gene regulation in rat soleus muscle J Appl Physiol, April 1, 2005; 98(4): 1185 - 1194. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. J. Caiozzo, Y. Z. Wu, M. J. Baker, and R. Crumley Effects of Denervation on Cell Cycle Control in Laryngeal Muscle Arch Otolaryngol Head Neck Surg, September 1, 2004; 130(9): 1056 - 1068. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Ishido, K. Kami, and M. Masuhara In vivo expression patterns of MyoD, p21, and Rb proteins in myonuclei and satellite cells of denervated rat skeletal muscle Am J Physiol Cell Physiol, August 1, 2004; 287(2): C484 - C493. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Maier and A. Bornemann M-cadherin transcription in satellite cells from normal and denervated muscle Am J Physiol Cell Physiol, March 1, 2004; 286(3): C708 - C712. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
