Monosynaptic Stochastic Stimulation of Spinal Motoneurones in the Cat

Abstract

THE artificial nature of a synchronous afferent volley was pointed out many years ago1 and, although neurophysiological knowledge has been considerably advanced by use of the synchronous volley technique, it has definite limitations in providing a full understanding of reflex mechanisms in the intact animal. Each annulo-spinal ending in a muscle under tension discharges in a quasi-periodic manner, and the differing stretch thresholds in these receptors2 cause the average discharge frequency of each ending to differ. The timing of the initiation of impulses in one ending will be statistically independent of the times of occurrence of impulses in other endings. The convergence of these asynchronous impulse patterns onto a particular motoneurone represents a situation very different from that of synchronous stimulation and introduces the effects of temporal summation. If the object of the experiment is to establish relationships between afferent and reflex impulse patterns, natural stimulation by stretching muscle has severe limitations, because the temporal impulse patterns arriving at a particular motoneurone cannot be obtained. In the experiments described here, an attempt has been made to overcome this problem while retaining a stimulus which is physiologically realistic.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1

    Creed, R. S., Denny-Brown, D., Eccles, J. C., Lidell, E. G. T., and Sherrington, C. S., in Reflex Activity of the Spinal Cord (Clarendon Press, Oxford. 1932).

    Google Scholar 

  2. 2

    Hunt, C. C., J. Gen. Physiol., 38, 117 (1954).

    CAS  Article  Google Scholar 

  3. 3

    Henneman, E., Somjen, G., and Carpenter, D. O., J. NeuroPhysiol., 28, 560 (1965).

    CAS  Article  Google Scholar 

  4. 4

    Henatasch, H. D., Schulte, F. J., and Busch, G., Pflüg. Arch. Ges. Physiol., 270, 161 (1959).

    Article  Google Scholar 

  5. 5

    Granit, R., Phillips, C. G., Skoglund, S., and Steg, G., J. Neurophysiol., 20, 470 (1957).

    CAS  Article  Google Scholar 

  6. 6

    Alvord, jun., E. C., and Fuortes, M. G. F., J. Physiol., 122, 302 (1953).

    Article  Google Scholar 

  7. 7

    Lloyd, D. P. C., J. Gen. Physiol., 40, 435 (1957).

    CAS  Article  Google Scholar 

  8. 8

    Granit, R., Haase, J., and Rutledge, L. T., J. Physiol., 154, 308 (1960).

    CAS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

REDMAN, S., LAMPARD, D. Monosynaptic Stochastic Stimulation of Spinal Motoneurones in the Cat. Nature 216, 921–922 (1967). https://doi.org/10.1038/216921a0

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.