Studies of excitable membranes. II. A comparison of specializations at neuromuscular junctions and nonjunctional sarcolemmas of mammalian fast and slow twitch muscle fibers

doi:10.1083/jcb.68.3.752

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Studies of excitable membranes. II. A comparison of specializations at neuromuscular junctions and nonjunctional sarcolemmas of mammalian fast and slow twitch muscle fibers

MH Ellisman, JE Rash, LA Staehelin and KR Porter

Mammalian fast and slow twitch skeletal muscles are compared by freeze- fracture, thick and thin sectioning, and histochemical techniques using conventional and high voltage electron microscopy. Despite gross morphological differences in endplate structure visualized at relatively low magnifications in this sections, rat extensor digitorum longus (EDL) (fast twitch) and soleus (slow twitch) fibers cannot be distinguished on the basis of size, number, or distribution of molecular specializations of the pre- and postsynaptic junctional membranes exposed by freeze fracturing. Specializations in the cortex of the juxtaneuronal portions of the junctional folds are revealed by high voltage electron stereomicroscopy as a branching, ladder-like filamentous network associated with the putative acetylcholline receptor complexes. These filaments are considered to be involved in restricting the mobility of receptor proteins to the perineuronal aspects of the postynaptic membrane. Although the junctional membranes of both EDL and soleus appear similar, a differential specialization of the secondary synaptic cleft was noted. The extracellular matrix in the bottom of soleus clefts was observed as an ordered system of filamentous "combs," These filamentous arrays have not been detected in EDL junctions. Examination of the extrajunctional sarcolemmas of EDL and soleus reveal additional differences which may be correlated with variations in electrical and contractile properties. For example, particle aggregates termed "square arrays" previously described in the sarcolemmas of some fibers of the rat diaphragm were observed in large numbers in sarcolemmas of EDL fibers but were seldom encountered in soleus fibers. These gross compositional differences in the membranes are discussed in the light of functional differences between fiber types.
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Rash, J. E., Yasumura, T., Hudson, C. S., Agre, P., Nielsen, S. (1998). Direct immunogold labeling of aquaporin-4 in square arrays of astrocyte and ependymocyte plasma membranes in rat brain and spinal cord. Proc. Natl. Acad. Sci. USA 95: 11981-11986 [Abstract] [Full Text]
Verbavatz, J., Ma, T, Gobin, R, Verkman, A. (1997). Absence of orthogonal arrays in kidney, brain and muscle from transgenic knockout mice lacking water channel aquaporin-4. J. Cell Sci. 110: 2855-2860 [Abstract]
Yang, B., Brown, D., Verkman, A. S. (1996). The Mercurial Insensitive Water Channel (AQP-4) Forms Orthogonal Arrays in Stably Transfected Chinese Hamster Ovary Cells. J. Biol. Chem. 271: 4577-4580 [Abstract] [Full Text]
Frigeri, A, Gropper, M., Umenishi, F, Kawashima, M, Brown, D, Verkman, A. (1995). Localization of MIWC and GLIP water channel homologs in neuromuscular, epithelial and glandular tissues. J. Cell Sci. 108: 2993-3002 [Abstract]
Verbavatz, J., Van Hoek, A., Ma, T, Sabolic, I, Valenti, G, Ellisman, M., Ausiello, D., Verkman, A., Brown, D (1994). A 28 kDa sarcolemmal antigen in kidney principal cell basolateral membranes: relationship to orthogonal arrays and MIP26. J. Cell Sci. 107: 1083-1094 [Abstract]
Kao, I, Drachman, D., Price, D. (1976). Botulinum toxin: mechanism of presynaptic blockade. Science 193: 1256-1258 [Abstract]