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.

Bidirectional modification of CA1 synapses in the adult hippocampus in vivo


MEMORIES are believed to be stored by synaptic modifications. One type of activity-dependent synaptic modification, long-term potentiation (LTP), has received considerable attention as a possible memory mechanism, particularly in hippocampus1. However, use-dependent decreases in synaptic strength can store information as well. A form of homosynaptic long-term depression (LTD) has been described and widely studied in the CA1 region of the developing hippocampus in vitro2–4. However, the relevance of this model of LTD to memory has been questioned because of failures to replicate it in the adult brain in vitro5 and, more recently, in vivo6. Here we re-examine this important issue and find that homosynaptic LTD can in fact be elicited in the adult hippocampus in vivo, that it has all the properties described in immature CA1 in vitro, and that LTD and LTP are reversible modifications of the same Schaffer collateral synapses. Thus homosynaptic LTD is not peculiar to brain slices, nor is it only of developmental significance. Rather, our data suggest that the mechanisms of LTP and LTD may be equal partners in the mnemonic operations of hippocampal neural networks.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Bliss, T. V. P. & Collingridge, G. L. Nature 361, 31–39 (1993).

    ADS  CAS  Article  Google Scholar 

  2. 2

    Dudek, S. M. & Bear, M. F. Proc. natn. Acad. Sci. U.S.A. 89, 4363–4367 (1992).

    ADS  CAS  Article  Google Scholar 

  3. 3

    Mulkey, R. M. & Malenka, R. C. Neuron 9, 967–975 (1992).

    CAS  Article  Google Scholar 

  4. 4

    Bear, M. F. & Malenka, R. C. Curr. Opin. Neurobiol. 4, 389–399 (1994).

    CAS  Article  Google Scholar 

  5. 5

    Bashir, Z. I. & Collingridge, G. L. Expl. Brain Res. 100, 437–43 (1994).

    CAS  Article  Google Scholar 

  6. 6

    Errington, M. L. et al. J. Neurophysiol. 74, 1793–1799 (1995).

    CAS  Article  Google Scholar 

  7. 7

    Abraham, W. & Mason, S. Brain Res. 462, 40–46 (1988).

    CAS  Article  Google Scholar 

  8. 8

    Thiels, E., Barrionuevo, G. & Berger, T. W. J. Neurophysiol. 71, 3009–3016 (1994).

    Article  Google Scholar 

  9. 9

    Kerr, D. S. & Abraham, W. C. Proc. natn. Acad. Sci. U.S.A. 92, 11637–11641 (1995).

    ADS  CAS  Article  Google Scholar 

  10. 10

    Breese, C., Hampson, R. & Deadwyler, S. J. Neurosci. 9, 1097–1111 (1989).

    CAS  Article  Google Scholar 

  11. 11

    Wilson, M. & McNaughton, B. Science 261, 1055–1058 (1993).

    ADS  CAS  Article  Google Scholar 

  12. 12

    Bienenstock, E. L., Cooper, L. N. & Munro, P. W. J. Neurosci. 2, 32–48 (1982).

    CAS  Article  Google Scholar 

Download references

Author information



Rights and permissions

Reprints and Permissions

About this article

Cite this article

Heynen, A., Abraham, W. & Bear, M. Bidirectional modification of CA1 synapses in the adult hippocampus in vivo. Nature 381, 163–166 (1996).

Download citation

Further reading


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