Journal of comparative physiology

, Volume 121, Issue 3, pp 413–431 | Cite as

Motoneurons innervating the dorsal superficial muscles of the hermit crab,Pagurus pollicarus, and their reflex asymmetry

  • William D. Chapple
Article

Summary

  1. 1.

    The morphology of the second ganglionic roots and motoneurons innervating the dorsal superficial muscles of the fourth abdominal segment of the hermit crab,Pagurus pollicarus, is described. No significant differences between left and right sides in axon diameters of fibers in the root above 2 μn nor in soma diameters filled with cobalt centripetally diffused in the second root were observed.

     
  2. 2.

    Five excitors and two inhibitors innervate the three subregions of the dorsal superficial muscles previously described (Chappie, 1977). The largest excitor innervates the phasic central medial region, a large inhibitor (next in size) innervates muscles in all three regions, a smaller excitor distributes to all the muscle fibers, and three excitors, similar in extracellular amplitude and conduction velocity innervate different subregions. The smallest fiber is an inhibitor that innervates the tonic muscles.

     
  3. 3.

    The three small excitors fire at different tonic frequencies. Pairs of bilateral homologues are physiologically asymmetrical in their tonic frequencies: those on the left fire at higher frequencies than those on the right.

     
  4. 4.

    Conduction velocities of motoneurons in left and right second roots do not differ significantly.

     
  5. 5.

    It appears that the source of the asymmetry is not located in the motoneurons, but arises centrally in the absence of any major peripheral asymmetry.

     
  6. 6.

    Numbers and relative sizes of motoneurons are more conservative in evolution than reflex connections and the details of innervation of the muscle fibers.

     

Keywords

Cobalt Muscle Fiber Relative Size Conduction Velocity Medial Region 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alexandrowicz, J.S.: Muscle receptor organs in the Paguridae. J. Mar. Biol. Soc. U.K.31, 277–286 (1952)Google Scholar
  2. Barrett, J.N., Crill, W.E.: Specific membrane properties of cat motoneurones. J. Physiol.239, 301–324 (1974)Google Scholar
  3. Bent, S.A., Chappie, W.D.: Simplification of swimmeret musculature and innervation in the hermit crab,Pagurus pollicarus, in comparison to macrurans. J. comp. Physiol.118, 61–73 (1977)Google Scholar
  4. Bittner, G.D., Traut, D.L.: Growth of crustacean muscles and muscle fibers: constancy of fiber number and sarcomere number. J. comp. Physiol., in press (1978)Google Scholar
  5. Bullock, T.H., Horridge, G.A.: Structure and function in the nervous system of invertebrates. San Francisco: W.H. Freeman & Co. 1965Google Scholar
  6. Burke, R.E., Edgerton, V.R.: Motor unit properties and selective involvement in movement. In: Exercise and sport sciences reviews, Vol. 3 (ed. J.H. Wilmore, J.F. Keogh), pp. 31–81. New York: Academic Press 1975Google Scholar
  7. Chapple, W.D.: Sensory modalities and receptive fields in the abdominal nervous system of the hermit crab,Pagurus granosimanus (Stimpson). J. exp. Biol.44, 209–223 (1966)Google Scholar
  8. Chapple, W.D.: Postural control of shell position by the abdomen of the hermit crab,Pagurus pollicarus. I. Morphology of the superficial muscles and their nerves. J. exp. Zool.171, 397–408 (1969a)Google Scholar
  9. Chapple, W.D.: Postural control of shell position by the abdomen of the hermit crab,Pagurus pollicarus. II. Reflex control of the ventral superficial muscles. J. exp. Zool.171, 409–416 (1969b)Google Scholar
  10. Chapple, W.D.: Hydrostatic pressure changes in the abdomen of the hermit crab,Pagurus pollicarus, during movement. J. comp. Physiol.88, 399–412 (1974)Google Scholar
  11. Chapple, W.D.: Role of asymmetry in the functioning of invertebrate nervous systems. In: Lateralization in the nervous system (ed. R.W. Doty, L. Goldstein, S.R. Harnad, J. Jaynes, C. Krauthamer). New York: Academic Press 1976Google Scholar
  12. Chapple, W.D.: Diversity of muscle fibers in the abdominal dorsal superficial muscles of the hermit crab,Pagurus pollicarus. J. comp. Physiol.121, 395–412 (1977)Google Scholar
  13. Chapple, W.D., Hearney, E.S.: The morphology of the fourth abdominal ganglion of the hermit crab: a light microscope study. J. Morph.144, 407–420 (1974)Google Scholar
  14. Clough, J.F.M., Kernell, D., Phillips, C.G.: Conduction velocity in proximal and distal portions of forelimb axons in the baboon. J. Physiol.198, 167–178 (1968)Google Scholar
  15. Davis, W.J.: Functional significance of motoneuron size and soma position in swimmeret system of the lobster. J. Neurophysiol.34, 274–288 (1971)Google Scholar
  16. Evoy, W.H.: Modulation of proprioceptive information in crustacea. In: Neural control of locomotion (ed. R.M. Herman, S. Grillner, P.S.G. Stein, D.G. Stuart). New York: Plenum Press 1976Google Scholar
  17. Fields, H., Evoy, W.H., Kennedy, D.: Reflex role played by efferent control of an invertebrate stretch receptor. J. Neurophysiol.30, 859–874 (1967)Google Scholar
  18. Grimby, L., Hannerz, J.: Recruitment order of motor units on voluntary contraction; changes induced by proprioceptive afferent activity. J. Neurol. Neurosurg. Psychiat.31, 565–573 (1968)Google Scholar
  19. Grimby, E., Hannerz, J.: Differences in recruitment order of motor units in phasic and tonic flexion reflex in ‘spinal man’. J. Neurol. Neurosurg. Psychiat.33, 562–570 (1970)Google Scholar
  20. Henneman, E., Somjen, G., Carpenter, D.O.: Functional significance of cell size in spinal motoneurons. J. Neurophysiol.28, 560–580 (1965)Google Scholar
  21. Jahromi, S.S., Atwood, H.L.: Correlation of structure, speed of contraction, and total tension in fast and slow abdominal muscle fibers of the lobster,Homarus americanus. J. exp. Zool.171, 25–38 (1968)Google Scholar
  22. Kahan, L.B.: Neural control of postural muscles inCallianassa californiensis and three other species of decapod crustaceans. Comp. Biochem. Physiol.40A, 1–18 (1971)Google Scholar
  23. Kennedy, D.: The Reflex Control of Muscle. In: Invertebrate nervous systems pp. 197–212. Chicago: U. Chicago Press 1967Google Scholar
  24. Kennedy, D., Takeda, K.: Reflex control of abdominal flexor muscles in the crayfish. II. The tonic system. J. exp. Biol.43, 229–246 (1965)Google Scholar
  25. King, D.G.: Organization of crustacean neuropil. I. Patterns of synaptic connection in lobster stomatogastric ganglion. J. Neurocyt.5, 207–237 (1976)Google Scholar
  26. Kuffler, S.W., Edwards, C.: Mechanism of gamma aminobutyric acid (Gaba) action and its relation to synaptic inhibition. J. Neurophysiol.21, 589–610 (1958)Google Scholar
  27. Marrelli, J.D.: The morphology and activation of the deep abdominal motor system of the hermit crab,Pagurus pollicarus (Sag.) and the homologous relationship to the crayfish deep abdominal motor system. Ph. D. dissertation: U. Conn. Storrs, Ct. (1975)Google Scholar
  28. Mendell, E.M., Munson, J.B., Scott, J.G.: Alterations of synapses on axotomized motoneurons. J. Physiol.255, 67–79 (1976)Google Scholar
  29. Parnas, I., Atwood, H.L.: Phasic and tonic neuromuscular systems in the abdominal extensor muscles of the crayfish and rock lobster. Comp. Biochem. Physiol.18, 701–723 (1966)Google Scholar
  30. Pilgrim, R.L.C.: Muscle receptor organs in some decapod crustacea. Comp. Biochem. Physiol.1, 248–257 (1960)Google Scholar
  31. Pilgrim, R.L.C.: Stretch receptor organs in the thorax of the hermit crab,Pagurus bernhardus (L.). J. Mar. biol. Ass. U.K.54, 13–24 (1974)Google Scholar
  32. Selvin-Testa, A., Urbina-Vidai, C.: Axon-glia relationships in crab nerves. J. Neurocyt.4, 23–31 (1975)Google Scholar
  33. Smith, D.O., Hatt, H.: Axon conduction block in a region of dense connective tissue in crayfish. J. Neurophysiol.39, 794–801 (1976)Google Scholar
  34. Sokolove, P.G. and Tatton, W.G.: Analysis of postural motoneuron activity in crayfish abdomen. I. Cordination by premotoneuron connections. J. Neurophysiol.38, 313–331 (1975)Google Scholar
  35. Stein, R.B., Pearson, K.G.: Predicted amplitude and form of action potentials recorded from unmyelinated nerve fibres. J. theor. Biol.32, 539–558 (1971)Google Scholar
  36. Strausfeld, N.J., Obermayer, M.: Resolution of intraneuronal and transynaptic migration of cobalt in the insect visual and central nervous systems. J. comp. Physiol.110, 1–12 (1976)Google Scholar
  37. Wiens, T. J.: Electrical and structural properties of crayfish claw motoneurons in a isolated clawganglion preparation. J. comp. Physiol.112, 213–233 (1976)Google Scholar
  38. Wiersma, C.A.G., Ripley, S.H.: Innervation patterns of crustacean limbs. Physiol. Comp.2, 391–405 (1952)Google Scholar
  39. Wiese, K.: Mechanoreceptors for near-field water displacements in crayfish. J. Neurophysiol.39, 816–833 (1976)Google Scholar
  40. Wyman, R.J., Waldron, I., Wachtel, G.M.: Eack of fixed order of recruitment in cat motoneuron pools. Exp. Brain Res.20, 101–114 (1974)Google Scholar
  41. Zucker, R.S.: Theoretical implications of the size principle of motoneuron recruitment. J. theor. Biol.38, 587–596 (1973)Google Scholar

Copyright information

© Springer-Verlag 1977

Authors and Affiliations

  • William D. Chapple
    • 1
  1. 1.Physiology Section, Biological Sciences GroupUniversity of ConnecticutStorrsUSA

Personalised recommendations