Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

Synaptic Activity and Connective Tissue Remodeling in Denervated Frog Muscle

Elizabeth A. Connor, Ke Qin, Haya Yankelev and Diana DeStefano
The Journal of Cell Biology
Vol. 127, No. 5 (Dec., 1994), pp. 1435-1445
Stable URL: http://www.jstor.org/stable/1616558
Page Count: 11
  • More info
  • Cite this Item
Synaptic Activity and Connective Tissue Remodeling in Denervated Frog Muscle
Preview not available

Abstract

Denervation of skeletal muscle results in dramatic remodeling of the cellular and molecular composition of the muscle connective tissue. This remodeling is concentrated in muscle near neuromuscular junctions and involves the accumulation of interstitial cells and several extracellular matrix molecules. Given the role of extracellular matrix in neurite outgrowth and synaptogenesis, we predict that this remodeling of the junctional connective tissue directly influences the regeneration of the neuromuscular junction. As one step toward understanding the role of this denervation-induced remodeling in synapse formation, we have begun to look for the signals that are involved in initiating the junctional accumulations of interstitial cells and matrix molecules. Here, the role of muscle inactivity as a signal was examined. The distributions of interstitial cells, fibronectin, and tenascin were determined in muscles inactivated by presynaptic blockade of muscle activity with tetrodotoxin. We found that blockade of muscle activity for up to 4 wk produced neither the junctional accumulation of interstitial cells nor the junctional concentrations of tenascin and fibronectin normally present in denervated frog muscle. In contrast, the muscle inactivity induced the extrajunctional appearance of two synapse-specific molecules, the acetylcholine receptor and a muscle fiber antigen, mAb 3B6. These results demonstrate that the remodeling of the junctional connective tissue in response to nerve injury is a unique response of muscle to denervation in that it is initiated by a mechanism that is independent of muscle activity. Thus connective tissue remodeling in denervated skeletal muscle may be induced by signals released from or associated with the nerve other than the evoked release of neurotransmitter.

Page Thumbnails

  • Thumbnail: Page 
1435
    1435
  • Thumbnail: Page 
1436
    1436
  • Thumbnail: Page 
1437
    1437
  • Thumbnail: Page 
1438
    1438
  • Thumbnail: Page 
1439
    1439
  • Thumbnail: Page 
1440
    1440
  • Thumbnail: Page 
1441
    1441
  • Thumbnail: Page 
1442
    1442
  • Thumbnail: Page 
1443
    1443
  • Thumbnail: Page 
1444
    1444
  • Thumbnail: Page 
1445
    1445