We thank Mr. C. D. Foreman for technical assistance.
Article first published online: 23 FEB 2005
Copyright © 1966 Wiley-Liss, Inc.
The Anatomical Record
Volume 155, Issue 1, pages 1–10, May 1966
How to Cite
Walker, S. M. and Schrodt, G. R. (1966), Connections between the T system and sarcoplasmic reticulum. Anat. Rec., 155: 1–10. doi: 10.1002/ar.1091550102
This work was aided by NSF grant GB-2009 and NIH grant NB 05444–01.
- Issue published online: 23 FEB 2005
- Article first published online: 23 FEB 2005
Electron micrographs of rat gastrocnemius muscle fibers show membrane-like dense structures traversing the space between the transverse system (T) and the terminal segments of sarcoplasmic reticulum (R). The periodicity of the structures, viewed in longitudinal sections of triads, varies from 150–250 Å. The distance between apposed membranes of T and R is 80–100 Å at the level of the dense structures between T and R. The distance is slightly greater than 100 Å at the level of less dense areas which alternate with the dense structures. The scalloped appearance of the R membrane, associated with differences in distance between T and R when the levels of dense structures and less dense areas are compared, leads to the suggestion that a holding force might be exerted by the dense structures. Such a holding force would support the view that the membrane-like dense structures are indeed connections between T and R. If membrane-like connections between T and R completely surround the less dense areas it is possible that a “physiological tight junction” conductive to electrotonic spread of current might exist between apposed membranes of T and R.