Skip to main content
NCBI home page
The Journal of Cell Biology logoLink to The Journal of Cell Biology
. 1964 Dec 1;23(3):553–585. doi: 10.1083/jcb.23.3.553

A STUDY OF THE STRUCTURE AND DISTRIBUTION OF THE NEXUS

M M Dewey 1, L Barr 1
PMCID: PMC2106539  PMID: 14245436

Abstract

Nexuses, that is, fusions of plasma membranes of adjacent cells, are described in mammalian smooth and cardiac muscle, median giant axon of earthworm, frog skin, and rat submandibular gland. In smooth muscle they usually occur where a process from one cell either meets a process of, or projects into a neighboring cell. On the other hand, in mammalian heart muscle and in earthworm giant axon the nexuses occur along the intercalated disc and intercellular segmental septa, respectively. Their occurrence between these excitable cells is correlated with propagation of action potentials by an electrical rather than chemical mechanism. Since the nexuses may offer pathways for electric current between cell interiors, it seems possible that they constitute a link in the structural basis for electrical transmission in these systems. In epithelia, nexuses usually appear as part of a terminal bar complex. This is true in the rat salivary gland studied here. In the epidermis of frog skin, nexuses are less numerous between the basilar columnar cells than between the subjacent squamous cells. The nexuses which occur in epithelia in frog skin and rat salivary gland are distributed as though to provide seals against electrochemical backleaks and sites of chemical exchange between cell interiors.

Full Text

The Full Text of this article is available as a PDF (4.3 MB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. BARR L., BERGER W. THE ROLE OF CURRENT FLOW IN THE PROPAGATION OF CARDIAC MUSCLE ACTION POTENTIALS. Pflugers Arch Gesamte Physiol Menschen Tiere. 1964 Apr 13;279:192–194. doi: 10.1007/BF00412779. [DOI] [PubMed] [Google Scholar]
  2. BENNETT M. V., ALJURE E., NAKAJIMA Y., PAPPAS G. D. Electrotonic junctions between teleost spinal neurons: electrophysiology and ultrastructure. Science. 1963 Jul 19;141(3577):262–264. doi: 10.1126/science.141.3577.262. [DOI] [PubMed] [Google Scholar]
  3. BERGMAN R. A. Intercellular bridges in ureteral smooth muscle. Bull Johns Hopkins Hosp. 1958 Apr;102(4):195–202. [PubMed] [Google Scholar]
  4. Barr L. Propagation in vertebrate visceral smooth muscle. J Theor Biol. 1963 Jan;4(1):73–85. doi: 10.1016/0022-5193(63)90101-2. [DOI] [PubMed] [Google Scholar]
  5. CAESAR R., EDWARDS G. A., RUSKA H. Architecture and nerve supply of mammalian smooth muscle tissue. J Biophys Biochem Cytol. 1957 Nov 25;3(6):867–878. doi: 10.1083/jcb.3.6.867. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. CHOI J. K. The fine structure of the urinary bladder of the toad, Bufo marinus. J Cell Biol. 1963 Jan;16:53–72. doi: 10.1083/jcb.16.1.53. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. COGGESHALL R. E., FAWCETT D. W. THE FINE STRUCTURE OF THE CENTRAL NERVOUS SYSTEM OF THE LEECH, HIRUDO MEDICINALIS. J Neurophysiol. 1964 Mar;27:229–289. doi: 10.1152/jn.1964.27.2.229. [DOI] [PubMed] [Google Scholar]
  8. CURTIS H. J., TRAVIS D. M. Conduction in Purkinje tissue of the ox heart. Am J Physiol. 1951 Apr 1;165(1):173–178. doi: 10.1152/ajplegacy.1951.165.1.173. [DOI] [PubMed] [Google Scholar]
  9. DEWEY M. M. The ultrastructure of mammalian cell membranes. Med Bull (Ann Arbor) 1959 May;25(5):132–147. [PubMed] [Google Scholar]
  10. Dewey M. M., Barr L. Intercellular Connection between Smooth Muscle Cells: the Nexus. Science. 1962 Aug 31;137(3531):670–672. doi: 10.1126/science.137.3531.670-a. [DOI] [PubMed] [Google Scholar]
  11. FARQUHAR M. G., PALADE G. E. Junctional complexes in various epithelia. J Cell Biol. 1963 May;17:375–412. doi: 10.1083/jcb.17.2.375. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. FRANKENHAEUSER B., HODGKIN A. L. The after-effects of impulses in the giant nerve fibres of Loligo. J Physiol. 1956 Feb 28;131(2):341–376. doi: 10.1113/jphysiol.1956.sp005467. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. HAGIWARA S., TASAKI I. A study on the mechanism of impulse transmission across the giant synapse of the squid. J Physiol. 1958 Aug 29;143(1):114–137. doi: 10.1113/jphysiol.1958.sp006048. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. HAMA K. Some observations on the fine structure of the giant fibers of the crayfishes (Cambarus virilus and Cambarus clarkii) with special reference to the submicroscopic organization of the synapses. Anat Rec. 1961 Dec;141:275–293. doi: 10.1002/ar.1091410403. [DOI] [PubMed] [Google Scholar]
  15. HARMAN J. W., O'HEGARTY M. T., BYRNES C. K. The ultrastructure of human smooth muscle. I. Studies of cell surface and connections in normal and achalasia esophageal smooth muscle. Exp Mol Pathol. 1962 Jun;1:204–228. doi: 10.1016/0014-4800(62)90021-7. [DOI] [PubMed] [Google Scholar]
  16. ITO S., WINCHESTER R. J. The fine structure of the gastric mucosa in the bat. J Cell Biol. 1963 Mar;16:541–577. doi: 10.1083/jcb.16.3.541. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. KANNO Y., LOEWENSTEIN W. R. INTERCELLULAR DIFFUSION. Science. 1964 Feb 28;143(3609):959–960. doi: 10.1126/science.143.3609.959. [DOI] [PubMed] [Google Scholar]
  18. KAO C. Y., GRUNDFEST H. Postsynaptic electrogenesis in septate giant axons. I. Earthworm median giant axon. J Neurophysiol. 1957 Nov;20(6):553–573. doi: 10.1152/jn.1957.20.6.553. [DOI] [PubMed] [Google Scholar]
  19. KARNOVSKY M. J. Simple methods for "staining with lead" at high pH in electron microscopy. J Biophys Biochem Cytol. 1961 Dec;11:729–732. doi: 10.1083/jcb.11.3.729. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. KARRER H. E. Cell interconnections in normal human cervical epithelium. J Biophys Biochem Cytol. 1960 Feb;7:181–184. doi: 10.1083/jcb.7.1.181. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. KUFFLER S. W., POTTER D. D. GLIA IN THE LEECH CENTRAL NERVOUS SYSTEM: PHYSIOLOGICAL PROPERTIES AND NEURON-GLIA RELATIONSHIP. J Neurophysiol. 1964 Mar;27:290–320. doi: 10.1152/jn.1964.27.2.290. [DOI] [PubMed] [Google Scholar]
  22. KURTZ S. M. A new method for embedding tissues in Vestopal W. J Ultrastruct Res. 1961 Oct;5:468–469. doi: 10.1016/s0022-5320(61)80020-8. [DOI] [PubMed] [Google Scholar]
  23. LUFT J. H. Improvements in epoxy resin embedding methods. J Biophys Biochem Cytol. 1961 Feb;9:409–414. doi: 10.1083/jcb.9.2.409. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. LUFT J. H. Permanganate; a new fixative for electron microscopy. J Biophys Biochem Cytol. 1956 Nov 25;2(6):799–802. doi: 10.1083/jcb.2.6.799. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. MERRILLEES N. C., BURNSTOCK G., HOLMAN M. E. CORRELATION OF FINE STRUCTURE AND PHYSIOLOGY OF THE INNERVATION OF SMOOTH MUSCLE IN THE GUINEA PIG VAS DEFERENS. J Cell Biol. 1963 Dec;19:529–550. doi: 10.1083/jcb.19.3.529. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. PALADE G. E. A study of fixation for electron microscopy. J Exp Med. 1952 Mar;95(3):285–298. doi: 10.1084/jem.95.3.285. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. PARAKKAL P. F., MATOLTSY A. G. A STUDY OF THE FINE STRUCTURE OF THE EPIDERMIS OF RANA PIPIENS. J Cell Biol. 1964 Jan;20:85–94. doi: 10.1083/jcb.20.1.85. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. PETERS A. Plasma membrane contacts in the central nervous system. J Anat. 1962 Apr;96:237–248. [PMC free article] [PubMed] [Google Scholar]
  29. PROSSER C. L., BURNSTOCK G., KAHN J. Conduction in smooth muscle: comparative structural properties. Am J Physiol. 1960 Sep;199:545–552. doi: 10.1152/ajplegacy.1960.199.3.545. [DOI] [PubMed] [Google Scholar]
  30. ROBERTSON J. D., BODENHEIMER T. S., STAGE D. E. THE ULTRASTRUCTURE OF MAUTHNER CELL SYNAPSES AND NODES IN GOLDFISH BRAINS. J Cell Biol. 1963 Oct;19:159–199. doi: 10.1083/jcb.19.1.159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. ROBERTSON J. D. THE OCCURRENCE OF A SUBUNIT PATTERN IN THE UNIT MEMBRANES OF CLUB ENDINGS IN MAUTHNER CELL SYNAPSES IN GOLDFISH BRAINS. J Cell Biol. 1963 Oct;19:201–221. doi: 10.1083/jcb.19.1.201. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. ROBERTSON J. D. The molecular structure and contact relationships of cell membranes. Prog Biophys Mol Biol. 1960;10:343–418. [PubMed] [Google Scholar]
  33. ROBERTSON J. D. Ultrastructure of excitable membranes and the crayfish median-giant synapse. Ann N Y Acad Sci. 1961 Sep 6;94:339–389. doi: 10.1111/j.1749-6632.1961.tb35552.x. [DOI] [PubMed] [Google Scholar]
  34. SJOSTRAND F. S., ANDERSSON-CEDERGREN E., DEWEY M. M. The ultrastructure of the intercalated discs of frog, mouse and guinea pig cardiac muscle. J Ultrastruct Res. 1958 Apr;1(3):271–287. doi: 10.1016/s0022-5320(58)80008-8. [DOI] [PubMed] [Google Scholar]
  35. STOECKENIUS W. Some electron microscopical observations on liquid-crystalline phases in lipid-water systems. J Cell Biol. 1962 Feb;12:221–229. doi: 10.1083/jcb.12.2.221. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. VOUTE C. L. AN ELECTRON MICROSCOPIC STUDY OF THE SKIN OF THE FROG (RANA PIPIENS). J Ultrastruct Res. 1963 Dec;52:497–510. doi: 10.1016/s0022-5320(63)80081-7. [DOI] [PubMed] [Google Scholar]
  37. WATSON M. L. Staining of tissue sections for electron microscopy with heavy metals. J Biophys Biochem Cytol. 1958 Jul 25;4(4):475–478. doi: 10.1083/jcb.4.4.475. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Cell Biology are provided here courtesy of The Rockefeller University Press

RESOURCES