Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

A New Spinal Flexor Reflex


IN the acute spinal animal L-3,4-dihydroxyphenyl-alanine (DOPA) gives a marked increase in the flexor reflex which can be evoked on pinching the skin1,2. An electrophysiological analysis revealed that DOPA depresses the transmission of single volleys from the flexor reflex afferents to motoneurones and to primary afferents3,4. DOPA is more effective in depressing the path from the flexor reflex afferents to primary afferents than to motoneurones. Hence there was the possibility that DOPA, by eliminating the negative feed-back of presynaptic inhibition (the primary afferent depolarization in the flexor reflex afferents), might give more effective transmission to motoneurones despite its inhibitory action on this path3. However, further experiments have shown that this explanation is not correct.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Magnusson, T., and Rosengren, E., Experientia, 19, 229 (1963).

    Google Scholar 

  2. Carlsson, A., Magnusson, T., and Rosengren, E., Experientia, 19, 359 (1963).

    Google Scholar 

  3. Andén, N. E., Lundberg, A., Rosengren, E., and Vyklický, Experientia, 19, 654 (1963).

    Article  Google Scholar 

  4. Andén, N. E., Jukes, M. G. M., and Lundberg, A., Nature, 202, 1222 (1964).

    Article  ADS  Google Scholar 

  5. Eccles, R. M., and Lundberg, A., Arch. ital. Biol., 97, 199 (1959).

    Google Scholar 

  6. Wall, P. D., J. Physiol. (Lond.), 142, 1 (1958).

    Article  CAS  Google Scholar 

  7. Eccles, J. C., Magni, F., and Willis, W. D., J. Physiol. (Lond.), 160, 62 (1962).

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

ANDÉN, N., JUKES, M., LUNDBERG, A. et al. A New Spinal Flexor Reflex. Nature 202, 1344–1345 (1964).

Download citation

  • Issue Date:

  • DOI:

This article is cited by


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.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing