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A transverse tubular system and neuromuscular junctions in a molluscan unstriated muscle

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Summary

The buccal mass retractor muscles of Philine aperta are unusual in possessing a system of transverse tubules in what are in other respects typical unstriated muscle fibres. The tubules are formed from invaginations of the sarcolemma that penetrate up to 9 μm radially into the fibre. There is some indication that the tubules are zoned at certain points along the fibre. Physiologically, the outer membrane of the muscle fibre does not support an action potential, and the fibre contracts by summation of small twitches in response to individual excitatory junction potentials. Neuromuscular junctions occur in shallow grooves along the surface of the fibres. They contain 3 types of vesicles; clear, intermediate and dense-cored. A scheme suggesting how striated muscle may be derived from the unstriated condition is described.

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References

  • Barrantes FJ (1970) The neuromuscular junctions of a pulmonate mollusc. I. Ultrastructural study. Z Zellforsch 104:205–212

    Google Scholar 

  • Brace RC (1977) The functional anatomy of the mantle complex and columellar muscle of tectibranch molluscs (Gastropoda: Opisthobranchia), and its bearing on the evolution of opistobranch organisation. Phil Trans R Soc Ser B 277:1–56

    Google Scholar 

  • Gerschenfeld HM (1963) Observations on the ultrastructure of synapses in some pulmonate molluscs. Z Zellforsch 60:258–275

    Google Scholar 

  • Heyer CB, Kater SB, Karlsson UL (1973) Neuromuscular systems in molluscs. Am Zool 13:247–270

    Google Scholar 

  • Josephson RK (1975) Extensive and intensive factors determining the performance of striated muscle. J Exp Zool 194:135–154

    Google Scholar 

  • Karnovsky MJ, Roots L (1964) A “direct colouring” thiocholine method for cholinesterases. J Histochem Cytochem 12:219–221

    Google Scholar 

  • Kobayashi M (1972) Electrical and mechanical activities in the radula protractor of a mollusc, Rapana thomasiana. J Comp Physiol 78:1–10

    Google Scholar 

  • Lewis PR, Shute CCD (1966) The distribution of cholinesterase in cholinergic neurons demonstrated ith the electron microscope. J Cell Sci 1:381–390

    Google Scholar 

  • Orkand PM, Orkand RK (1975) Neuromuscular junctions in the buccal mass of Aplysia: Fine structure and electrophysiology of excitatory transmission. J Neurophysiol 6:531–548

    Google Scholar 

  • Palay SL (1956) Synapses in the central nervous system. J Biophys Biochem Cytol 2:193–201

    Google Scholar 

  • Peachy LD (1965) The sarcoplasmic reticulum and transverse tubules of the frog's sartorius. J Cell Biol 25:209–231

    Google Scholar 

  • Peachy LD, Adrian RH (1973) Electrical properties of the transverse tubular system. In: Bourne GH (ed) The structure and function of muscle, vol III. Academic Press, New York London

    Google Scholar 

  • Plesch B (1977) An ultrastructural study of the musculature of the pond snail Lymnaea stagnalis (L.). Cell Tissue Res 180:317–340

    Google Scholar 

  • Prescott L, Brightman MW (1976) The sarcolemma of Aplysia smooth muscle in freeze-fracture preparations. Tissue and Cell 8:241–258

    Google Scholar 

  • Reynolds ES (1963) The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol 17:208–212

    Article  CAS  PubMed  Google Scholar 

  • Richardot M, Wautier J (1971) Une structure intermédiaire entre muscle lisse et muscle strié. La fibre musculaire du bulbe buccal de Ferrissia wautieri (Moll. Basomm. Ancylidae). Z Zellforsch 115:100–109

    Google Scholar 

  • Rogers DC (1968) Fine structure of smooth muscle and neuromuscular junctions in the optic tentacles of Helix aspersa and Limax flavus. Z Zellforsch 89:80–94

    Google Scholar 

  • Rogers DC (1969) Fine structure of smooth muscle and neuromuscular junctions in the foot of Helix aspersa. Z Zellforsch 99:315–335

    Google Scholar 

  • Sanger JW (1971) Sarcoplasmic reticulum in the cross-striated adductor muscle of the bay scallop, Aequipecten irridians. Z Zellforsch 118:156–161

    Google Scholar 

  • Sanger JW, Hill RB (1972) Ultrastructure of the radula protractor of Busycon canaliculatum, sarcolemmic tubules and sarcoplasmic reticulum. Z Zellforsch 127:314–322

    Google Scholar 

  • Watson SJ, Barchas JO (1977) Catecholamine histofluorescence using cryostat sectioning and glyoxylic acid in unperfused frozen brain: a detailed description of the technique. Histochem J 9:183–195

    Google Scholar 

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The authors would like to thank Dr. N. Runham for commenting on the original manuscript

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Dorsett, D., Roberts, J.B. A transverse tubular system and neuromuscular junctions in a molluscan unstriated muscle. Cell Tissue Res. 206, 251–260 (1980). https://doi.org/10.1007/BF00232769

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  • DOI: https://doi.org/10.1007/BF00232769

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