Abstract
Low resistance junctions between axons of crayfish ganglia are studied by freeze-fracture and negative staining. In freeze-fracture, fracture planes that go through a junctional membrane expose two faces, both internal, called face A and face B. Face A belongs to the internal membrane leaflet and faces the gap. Face B belongs to the external membrane leaflet and faces the axoplasm. Face A displays pits, 60–100 Å in diameter, arranged in a hexagonal array with a unit cell of ∼200 Å. An ∼25 Å bump is frequently seen at the center of each pit. Some pits are occupied by a globule ∼125 Å in diameter, which displays a central depression ∼25 Å in size. Face B contains globules also arranged in a fairly regular hexagonal pattern. The center-to-center distance between adjacent globules is most frequently ∼200 Å; however, occasionally certain globules are seen separated by a distance as short as ∼125 Å. The top surface of the globules occasionally displays a starlike profile and seems to contain a central depression ∼25 Å in diameter. In negatively stained preparations of membranes from the nerve cord, two types of membranes are seen containing a fairly regular pattern. In one, globules ∼95 Å in diameter form a hexagonal close packing with a unit cell of ∼95 Å. In the other, globules of the same size are organized in a larger hexagonal array with a unit cell of ∼155 Å (swollen arrangement). Some of the globules forming the swollen arrangement are seen containing six subunits. The six subunits form a hexagon which is skewed with respect to the main rows of hexagons in such a way that the subunits lie on rows which make an angle of ∼37° with the main rows.
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Selected References
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- Benedetti E. L., Emmelot P. Hexagonal array of subunits in tight junctions separated from isolated rat liver plasma membranes. J Cell Biol. 1968 Jul;38(1):15–24. doi: 10.1083/jcb.38.1.15. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bennett M. V. Physiology of electrotonic junctions. Ann N Y Acad Sci. 1966 Jul 14;137(2):509–539. doi: 10.1111/j.1749-6632.1966.tb50178.x. [DOI] [PubMed] [Google Scholar]
- Branton D. Fracture faces of frozen membranes. Proc Natl Acad Sci U S A. 1966 May;55(5):1048–1056. doi: 10.1073/pnas.55.5.1048. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chalcroft J. P., Bullivant S. An interpretation of liver cell membrane and junction structure based on observation of freeze-fracture replicas of both sides of the fracture. J Cell Biol. 1970 Oct;47(1):49–60. doi: 10.1083/jcb.47.1.49. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Flower N. E. A new junctional structure in the epithelia of insects of the order Dictyoptera. J Cell Sci. 1972 May;10(3):683–691. doi: 10.1242/jcs.10.3.683. [DOI] [PubMed] [Google Scholar]
- Flower N. E. Septate and gap junctions between the epithelial cells of an invertebrate, the mollusc Cominella maculosa. J Ultrastruct Res. 1971 Nov;37(3):259–268. doi: 10.1016/s0022-5320(71)80123-5. [DOI] [PubMed] [Google Scholar]
- Gilula N. B., Satir P. Septate and gap junctions in molluscan gill epithelium. J Cell Biol. 1971 Dec;51(3):869–872. doi: 10.1083/jcb.51.3.869. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goodenough D. A., Revel J. P. A fine structural analysis of intercellular junctions in the mouse liver. J Cell Biol. 1970 May;45(2):272–290. doi: 10.1083/jcb.45.2.272. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Loewenstein W. R. Permeability of membrane junctions. Ann N Y Acad Sci. 1966 Jul 14;137(2):441–472. doi: 10.1111/j.1749-6632.1966.tb50175.x. [DOI] [PubMed] [Google Scholar]
- McNutt N. S., Weinstein R. S. The ultrastructure of the nexus. A correlated thin-section and freeze-cleave study. J Cell Biol. 1970 Dec;47(3):666–688. doi: 10.1083/jcb.47.3.666. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 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]
- Payton B. W., Bennett M. V., Pappas G. D. Permeability and structure of junctional membranes at an electrotonic synapse. Science. 1969 Dec 26;166(3913):1641–1643. doi: 10.1126/science.166.3913.1641. [DOI] [PubMed] [Google Scholar]
- 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]
- Peracchia C., Mittler B. S. Fixation by means of glutaraldehyde-hydrogen peroxide reaction products. J Cell Biol. 1972 Apr;53(1):234–238. doi: 10.1083/jcb.53.1.234. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spycher M. A. Intercellular adhesions. An electron microscope study on freeze-etched rat hepatocytes. Z Zellforsch Mikrosk Anat. 1970;111(1):64–74. [PubMed] [Google Scholar]
- Staehelin L. A. Three types of gap junctions interconnecting intestinal epithelial cells visualized by freeze-etching. Proc Natl Acad Sci U S A. 1972 May;69(5):1318–1321. doi: 10.1073/pnas.69.5.1318. [DOI] [PMC free article] [PubMed] [Google Scholar]