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. 1976 Aug 1;70(2):419–439. doi: 10.1083/jcb.70.2.419

Low resistance junctions in crayfish. Structural changes with functional uncoupling

PMCID: PMC2109825  PMID: 820701

Abstract

Electrical uncoupling of crayfish septate lateral giant axons is paralleled by structural changes in the gap junctions. The changes are characterized by a tighter aggregation of the intramembrane particles and a decrease in the overall width of the junction and the thickness of the gap. Preliminary measurements indicate also a decrease in particle diameter. The uncoupling is produced by in vitro treatment of crayfish abdominal cords either with a Ca++, Mg++-free solution containing EDTA, followed by return to normal saline (Van Harreveld's solution), or with VAn Harreveld's solution containing dinitrophenol (DNP). The uncoupling is monitored by the intracellular recording of the electrical resistance at a septum between lateral giant axons. The junctions of the same septum are examined in thin sections; those of other ganglia of the same chain used for the electrical measurements are studied by freeze-fracture. In controls, most junctions contain a more or less regular array of particles repeating at a center to center distance of approximately 200 A. The overall width of the junctions is approximately 200 A and the gap thickness is 40-50 A. Vesicles (400-700 A in diameter) are closely apposed to the junctional membranes. In uncoupled axons, most junctions contain a hexagonal array of particles repeating at a center to center distance of 150-155 A. The overall width of the junctions is approximately 180 A and the gap thickness is 20-30 A. These junctions are usually curved and are rarely associated with vesicles. Isolated, PTA-stained junctions, also believed to be uncoupled, display similar structural features. There are reasons to believe that the changes in structure and permeability are triggered by an increase in the intracellular free Ca++ concentration. Most likely, the changes in permeability are caused by conformational changes in some components of the intramembrane particles at the gap junctions.

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Selected References

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  1. Almers W. Potassium conductance changes in skeletal muscle and the potassium concentration in the transverse tubules. J Physiol. 1972 Aug;225(1):33–56. doi: 10.1113/jphysiol.1972.sp009928. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Asada Y., Bennett M. V. Experimental alteration of coupling resistance at an electrotonic synapse. J Cell Biol. 1971 Apr;49(1):159–172. doi: 10.1083/jcb.49.1.159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Baker P. F., Blaustein M. P., Hodgkin A. L., Steinhardt R. A. The influence of calcium on sodium efflux in squid axons. J Physiol. 1969 Feb;200(2):431–458. doi: 10.1113/jphysiol.1969.sp008702. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Baker P. F., Hodgkin A. L., Ridgway E. B. Depolarization and calcium entry in squid giant axons. J Physiol. 1971 Nov;218(3):709–755. doi: 10.1113/jphysiol.1971.sp009641. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Blaustein M. P., Hodgkin A. L. The effect of cyanide on the efflux of calcium from squid axons. J Physiol. 1969 Feb;200(2):497–527. doi: 10.1113/jphysiol.1969.sp008704. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Branton D., Bullivant S., Gilula N. B., Karnovsky M. J., Moor H., Mühlethaler K., Northcote D. H., Packer L., Satir B., Satir P. Freeze-etching nomenclature. Science. 1975 Oct 3;190(4209):54–56. doi: 10.1126/science.1166299. [DOI] [PubMed] [Google Scholar]
  7. Bullivant S., Loewenstein W. R. Structure of coupled and uncoupled cell junctions. J Cell Biol. 1968 Jun;37(3):621–632. doi: 10.1083/jcb.37.3.621. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Carafoli E. In vivo effect of uncoupling agents on the incorporation of calcium and strontium into mitochondria and other subcellular fractions of rat liver. J Gen Physiol. 1967 Aug;50(7):1849–1864. doi: 10.1085/jgp.50.7.1849. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Carafoli E., Tiozzo R., Lugli G., Crovetti F., Kratzing C. The release of calcium from heart mitochondria by sodium. J Mol Cell Cardiol. 1974 Aug;6(4):361–371. doi: 10.1016/0022-2828(74)90077-7. [DOI] [PubMed] [Google Scholar]
  10. DRAHOTA Z., CARAFOLI E., ROSSI C. S., GAMBLE R. L., LEHNINGER A. L. THE STEADY STATE MAINTENANCE OF ACCUMULATED CA++ IN RAT LIVER MITOCHONDRIA. J Biol Chem. 1965 Jun;240:2712–2720. [PubMed] [Google Scholar]
  11. 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]
  12. Gage P. W., Eisenberg R. S. Capacitance of the surface and transverse tubular membrane of frog sartorius muscle fibers. J Gen Physiol. 1969 Mar;53(3):265–278. doi: 10.1085/jgp.53.3.265. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Goodenough D. A., Stoeckenius W. The isolation of mouse hepatocyte gap junctions. Preliminary chemical characterization and x-ray diffraction. J Cell Biol. 1972 Sep;54(3):646–656. doi: 10.1083/jcb.54.3.646. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. HODGKIN A. L., KEYNES R. D. Movements of labelled calcium in squid giant axons. J Physiol. 1957 Sep 30;138(2):253–281. doi: 10.1113/jphysiol.1957.sp005850. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Loewenstein W. R. Cell surface membranes in close contact. Role of calcium and magnesium ions. J Colloid Interface Sci. 1967 Sep;25(1):34–46. doi: 10.1016/0021-9797(67)90007-0. [DOI] [PubMed] [Google Scholar]
  16. Loewenstein W. R., Nakas M., Socolar S. J. Junctional membrane uncoupling. Permeability transformations at a cell membrane junction. J Gen Physiol. 1967 Aug;50(7):1865–1891. doi: 10.1085/jgp.50.7.1865. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Luxoro M., Yañez E. Permeability of the giant axon of Dosidicus gigas to calcium ions. J Gen Physiol. 1968 May;51(5 Suppl):115S+–115S+. [PubMed] [Google Scholar]
  18. Pappas G. D., Asada Y., Bennett M. V. Morphological correlates of increased coupling resistance at an electrotonic synapse. J Cell Biol. 1971 Apr;49(1):173–188. doi: 10.1083/jcb.49.1.173. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Payton B. W., Bennett M. V., Pappas G. D. Temperature-dependence of resistance at an electrotonic synapse. Science. 1969 Aug 8;165(3893):594–597. doi: 10.1126/science.165.3893.594. [DOI] [PubMed] [Google Scholar]
  20. Peracchia C. Excitable membrane ultrastructure. I. Freeze fracture of crayfish axons. J Cell Biol. 1974 Apr;61(1):107–122. doi: 10.1083/jcb.61.1.107. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Peracchia C. Low resistance junctions in crayfish. II. Structural details and further evidence for intercellular channels by freeze-fracture and negative staining. J Cell Biol. 1973 Apr;57(1):54–65. doi: 10.1083/jcb.57.1.54. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. 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]
  23. Revel J. P., Karnovsky M. J. Hexagonal array of subunits in intercellular junctions of the mouse heart and liver. J Cell Biol. 1967 Jun;33(3):C7–C12. doi: 10.1083/jcb.33.3.c7. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Rose B., Loewenstein W. R. Permeability of cell junction depends on local cytoplasmic calcium activity. Nature. 1975 Mar 20;254(5497):250–252. doi: 10.1038/254250a0. [DOI] [PubMed] [Google Scholar]
  25. SHIMOMURA O., JOHNSON F. H., SAIGA Y. Extraction, purification and properties of aequorin, a bioluminescent protein from the luminous hydromedusan, Aequorea. J Cell Comp Physiol. 1962 Jun;59:223–239. doi: 10.1002/jcp.1030590302. [DOI] [PubMed] [Google Scholar]
  26. Sato T. A modified method for lead staining of thin sections. J Electron Microsc (Tokyo) 1968;17(2):158–159. [PubMed] [Google Scholar]
  27. Staehelin L. A. Structure and function of intercellular junctions. Int Rev Cytol. 1974;39:191–283. doi: 10.1016/s0074-7696(08)60940-7. [DOI] [PubMed] [Google Scholar]
  28. VASINGTON F. D., MURPHY J. V. Ca ion uptake by rat kidney mitochondria and its dependence on respiration and phosphorylation. J Biol Chem. 1962 Aug;237:2670–2677. [PubMed] [Google Scholar]
  29. WATANABE A., GRUNDFEST H. Impulse propagation at the septal and commissural junctions of crayfish lateral giant axons. J Gen Physiol. 1961 Nov;45:267–308. doi: 10.1085/jgp.45.2.267. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Zampighi G., Robertson J. D. Fine structure of the synaptic discs separated from the goldfish medulla oblongata. J Cell Biol. 1973 Jan;56(1):92–105. doi: 10.1083/jcb.56.1.92. [DOI] [PMC free article] [PubMed] [Google Scholar]

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