On the Bulbospinal Locomotor Column in the Cat

  • O. V. Kazennikov
  • V. A. Selionov
  • M. L. Shik


Repetitive (30 to 60 pps) stimutation of the appropriate fibers at the medullary or spinal level elicits stepping. At both levels, there exist neurons which give synaptic responses even to single stimuli applied to the locomotor or stepping point. Most responses in the proximity of this stimulation site occur within 5–10 ms. Less than half of these responses are monosynaptic. This suggests the existence of strong excitatory interactions between neurons. Nevertheless the polysynaptic propagation of the activity evoked by a single stimulus was found to show a steep decrement and a significant temporal dispersion (up to 10 and even 30 ms). Further propagation of this activity is due to conduction along the fiber bundle.

Fibers of the stepping strip in the dorsolateral funiculus excite the stepping generator through the propriospinal neurons sending their axons into the ventrolateral funiculus.

Stepping can be elicited both by the direct bulbospinal pathway and via propriospinal neurons.


Single Stimulus Synaptic Response Cervical Segment Reticulospinal Neuron Step Point 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Brodai, A., 1957, The Reticular Formation of the Brain Stem, Oliver and Boyd, Edinburg.Google Scholar
  2. Clarke, J. D. W., and Roberts, A., 1984, Interneurons in the Xenopus embryo spinal cord: sensory excitation and activity during swimming, J. Physiol., 354: 345–362.PubMedGoogle Scholar
  3. Eidelberg, E.,1981, Consequences of spinal cord lesions upon motor function, with special reference to locomotor activity, Progr. Neurobiol., 17: 185–202.CrossRefGoogle Scholar
  4. Feldman, J. L., Loewy, A. D., and Speck, D. F., 1985, Projections from the ventral respiratory group to phrenic and intercostal motoneurons in cat: an autoradiographic study, J. Neurosci., 5: 1993–2000.PubMedGoogle Scholar
  5. Garcia-Rill, E., 1986, The basal ganglia and the locomotor regions, Brain Res. Rev., 11: 47–63.CrossRefGoogle Scholar
  6. Garcia-Rill, E., Skinner, R. D., and Gilmore, S. A., 1983, Owings R; Connections of the mesencephalic locomotor region (MLR). II. Afferents and efferents, Brain Res. Bull., 10: 63–71.PubMedCrossRefGoogle Scholar
  7. Grillner S. 1974. On the generation of locomotion in the spinal dogfish. Exp. Brain Res., 20: 159–170.CrossRefGoogle Scholar
  8. Kazennikov, O. V., Selionov, V. A., Shik, M. L., and Yakovleva, G. V., 1979, Neurons of upper cervical segments responding to stimulation of the bulbar “locomotor strip”, Neurophysiology (Kiev), 11: 245–253.PubMedGoogle Scholar
  9. Kazennikov, O. V., Shik, M. L., and Yakovleva, G. V., 1983a, Stepping movements elicited by stimulation of the dorsolateral funiculus in the cat spinal cord, Bull. Exper. Biol. Med. (Moscow), 96: 8–110.Google Scholar
  10. Kazennikov, O. V., Shik, M. L., and Yakovleva, G. V., 1983b, Responses of neurons of upper cervical segments in cat to stimulation of brain stem locomotor region with different frequences. Neurophysiology (Kiev). 15: 355–361.PubMedGoogle Scholar
  11. Kazennikov, O. V., Shik, M. L., and Yakovleva, G. V. 1985, Synaptic responses of propriospinal neurons to stimulation of the stepping strip in the cat dorsolateral funiculus, Neurophysiology (Kiev), 17: 270–278.PubMedCrossRefGoogle Scholar
  12. Lennard, P. R., and Stein, P. S. G., 1977, Swimming movements elicited by electrical stimulation of turtle spinal cord. I. Low-spinal and intact preparation, J. Neurophysiol., 40: 768–778.PubMedGoogle Scholar
  13. Lundberg, A., 1979, Integration in a propriospinal motor center controlling the forelimb in the cat. in: Integration in the Nervous System, A Symposium in Honor of D.P.C. Lloyd and R. Lorente de No, H. Asanuma, V.J. Wilson, eds.,47–65, Igaku-Shoin, Tokyo.Google Scholar
  14. McClellan, A. D., 1984, Descending control and sensory gating of “fictive” swimming and turning responses elicited in an in vitro preparation of the lamprey brain stem/spinal cord, Brain Res., 302: 151–162.PubMedCrossRefGoogle Scholar
  15. Mori, S., Selionov, V. A., and Shik, M. L., 1986, Responses of medullary neurons to stimulation of the locomotor and inhibitory points of the lower brain stem, Neurophysiology (Kiev), 18: 525–533.PubMedCrossRefGoogle Scholar
  16. Mori, S., Shik, M. L., and Yagodnitsyn, A. S., 1977, Role of pontine tegmentum for locomotor control in mesencephalic cat, J. Neurophysiol., 40: 284–295.PubMedGoogle Scholar
  17. Orlovsky, G. N., 1970, Work of the reticulspinal neurons during locomotion, Biophysics. 15: 728–734.Google Scholar
  18. Rovainen, C. M., 1985, Effects of groups of propriospinal interneurons on fictive swimming in the isolated spinal cord of the lamprey, J. Neurophysiol., 54: 959–977.PubMedGoogle Scholar
  19. Selionov, V. A., and Shik, M. L., 1981, Responses of medullary neurons to microstimulation of the “locomotor strip” in cat, Neurophysiology (Kiev), 13: 275–282.PubMedGoogle Scholar
  20. Selionov, V. A., and Shik, M. L., 1984, Medullary locomotor strip and column in the cat, Neurosci., 13: 1267–1278.CrossRefGoogle Scholar
  21. Shik, M. L., and Yagodnitsyn, A. S., 1977, The pontobulbar “locomotor strip”, Neurophysiology (Kiev), 9: 95–97.Google Scholar
  22. Shimamura, M., Kogure, L, and Wada, S. -I., 1982, Reticular neuron activities associated with locomotion in thalamic cats, Brain Res., 231: 51–62.CrossRefGoogle Scholar
  23. Soffe, S. R., and Roberts, A., 1982, Tonic and phasic synaptic input to spinal cord motoneurons during fictive locomotion in frog embryos, J. Neurophysiol., 48: 1279–1288.PubMedGoogle Scholar
  24. Steeves, J. D., and Jordan, L. M., 1980, Localization of a descending pathway in the spinal cord which is necessary for controlled treadmill locomotion, Neurosci. Lett., 20: 283–288.PubMedCrossRefGoogle Scholar
  25. Stein, P. S. G., 1978, Swimming movements elicited by electrical stimulation of the turtle spinal cord: the high spinal preparation. J. Comp. Physiol., 124: 203–210.CrossRefGoogle Scholar
  26. Williams, B. J., and Livingston, C. A., and Leonard, R. B., 1984, Spinal cord pathways involved in initiation of swimming in the stingray, Dasyatis sabina: spinal cord stimulation and lesions, J. Neurophysiol., 51: 578–591.PubMedGoogle Scholar
  27. Yamaguchi, T., 1981, Fictive stepping evoked by electrical stimulation of the white matter of the cervical cord in decerebrate cats, J. Physiol. Soc. Japan, 43: p. 303, Abstr. N 108.Google Scholar
  28. Yamaguchi, T., 1986, Descending pathway eliciting forelimb stepping in the lateral funiculus: experimental studies with stimulation and lesion of the cervical cord in decerebrate cats, Brain Res., 379: 125–136.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • O. V. Kazennikov
    • 1
  • V. A. Selionov
    • 1
  • M. L. Shik
    • 1
  1. 1.Institute of Information Transmission ProblemsAcademy of Sciences of the USSRMoscowRussia

Personalised recommendations