Skip to main content

Thank you for visiting nature.com. 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.

  • Letter
  • Published:

Time-dependent reorganization of brain circuitry underlying long-term memory storage

Abstract

Retrograde amnesia observed following hippocampal lesions in humans and animals is typically temporally graded1,2, with recent memory being impaired while remote memories remain intact, indicating that the hippocampal formation has a time-limited role in memory storage3,4. However, this claim remains controversial because studies involving hippocampal lesions tell us nothing about the contribution of the hippocampus to memory storage if this region was present at the time of memory retrieval5,6. We therefore used non-invasive functional brain imaging using (14C)2-deoxyglucose uptake to examine how the brain circuitry underlying long-term memory storage is reorganized over time in an intact brain. Regional metabolic activity in the brain was mapped in mice tested at different times for retention of a spatial discrimination task. Here we report that increasing the retention interval from 5 days to 25 days resulted in both decreased hippocampal metabolic activity during retention testing and a loss of correlation between hippocampal metabolic activity and memory performance. Concomitantly, a recruitment of certain cortical areas was observed. These results indicate that there is a time-dependent reorganization of the neuronal circuitry underlying long-term memory storage, in which a transitory interaction between the hippocampal formation and the neocortex would mediate the establishment of long-lived cortical memory representations.

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

Access options

Buy this article

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

Figure 1: Curves showing the progression of spatial discrimination performance over the nine daily sessions of initial acquisition and the retention.
Figure 2: Regional metabolic activity measured in the brains of mice as a function of the retention interval (5 days or 25 days) following initial acquisition (acq) of the spatial discrimination task.
Figure 3: (14C)2-deoxyglucose colour-coded autoradiographs.
Figure 4: Factor analysis showing clustering of response accuracy and metabolic activity in mouse brain regions during retention testing.

Similar content being viewed by others

References

  1. Reed, J. M. & Squire, L. R. Retrograde amnesia for facts and events: findings from four new cases. J. Neurosci. 18, 3943–3954 (1998).

    Article  CAS  Google Scholar 

  2. Squire, L. R. Memory and the hippocampus: a synthesis from findings with rats, monkeys and humans. Psychol. Rev. 99, 195–231 (1992).

    Article  CAS  Google Scholar 

  3. Zola-Morgan, S. M. & Squire, L. R. The primate hippocampal formation: evidence for a time-limited role in memory storage. Science 250, 288–290 (1990).

    Article  CAS  ADS  Google Scholar 

  4. Anagnostaras, S. G., Maren, S. & Fanselow, M. S. Temporally graded retrograde amnesia of contextual fear after hippocampal damage in rats: within-subjects examination. J. Neurosci. 19, 1106–1114 (1999).

    Article  CAS  Google Scholar 

  5. Moscovitch, M. & Nadel, L. Consolidation and the hippocampal complex revisited: in defense of the multiple-trace model. Curr. Opin. Neurobiol. 8, 297–300 (1998).

    Article  CAS  Google Scholar 

  6. Knowlton, B. J. & Fanselow, M. S. The hippocampus, consolidation and on-line memory. Curr. Opin. Neurobiol. 8, 293–296 (1998).

    Article  CAS  Google Scholar 

  7. Polster, M. R., Nadel, L. & Schacter, D. L. Cognitive neuroscience analysis of memory: a historical perspective. J. Cogn. Neurosci. 3, 95–116 (1991).

    Article  CAS  Google Scholar 

  8. Dudai, Y. Consolidation: fragility on the road to the engram. Neuron 17, 367–370 (1996).

    Article  CAS  Google Scholar 

  9. Squire, L. R. & Alvarez, P. Retrograde amnesia and memory consolidation: a neurobiological perspective. Curr. Opin. Neurobiol. 5, 169–177 (1995).

    Article  CAS  Google Scholar 

  10. Sokoloff, L.et al. The 14C-deoxyglucose method for measurement of local cerebral glucose utilization: theory, procedure and normal values in the conscious and anesthetized albino rat. J. Neurochem. 28, 897–916 (1977).

    Article  CAS  Google Scholar 

  11. Bontempi, B., Jaffard, R. & Destrade, C. Differential temporal evolution of post-training changes in regional brain glucose metabolism induced by repeated spatial discrimination training in mice: visualization of the memory consolidation process? Eur. J. Neurosci. 8, 2348–2360 (1996).

    Article  CAS  Google Scholar 

  12. Cho, Y. H., Beracochea, D. & Jaffard, R. Extended temporal gradient for the retrograde and anterograde amnesia produced by ibotenate entorhinal cortex lesions in mice. J. Neurosci. 13, 1759–1766 (1993).

    Article  CAS  Google Scholar 

  13. Finch, D. M., Derian, E. L. & Babb, T. L. Afferent fibers to rat cingulate cortex. Exp. Neurol. 83, 468–485 (1984).

    Article  CAS  Google Scholar 

  14. Sif, J., Meunier, M., Messier, C., Calas, A. & Destrade, C. Quantitative (14C)2-deoxyglucose study of a functional dissociation between anterior and posterior cingulate cortices in mice. Neurosci. Lett. 101, 223–228 (1989).

    Article  CAS  Google Scholar 

  15. Nyberg, L.et al. Network analysis of positron emission tomography regional cerebral blood flow data: ensemble inhibition during episodic memory retrieval. J. Neurosci. 16, 3753–3759 (1996).

    Article  CAS  Google Scholar 

  16. Teyler, T. J. & DiScenna, P. The hippocampal memory indexing theory. Behav. Neurosci. 100, 147–154 (1986).

    Article  CAS  Google Scholar 

  17. Damasio, A. R. Time-locked multiregional retroactivation: a systems-level proposal for the neural substrates of recall and recognition. Cognition 33, 25–62 (1989).

    Article  CAS  Google Scholar 

  18. O'Keefe, J. & Nadel, L. The Hippocampus as a Cognitive Map (Oxford Univ. Press, 1978).

    Google Scholar 

  19. Meunier, M., Jaffard, R. & Destrade, C. Differential involvement of anterior and posterior cingulate cortices in spatial discrimination learning in a T-maze in mice. Behav. Brain Res. 44, 133–143 (1991).

    Article  CAS  Google Scholar 

  20. Markowitsch, H. J. Which brain regions are critically involved in the retrieval of old episodic memory. Brain Res. Rev. 21, 117–127 (1995).

    Article  CAS  Google Scholar 

  21. Buckner, R. L., Kelley, W. M. & Petersen, S. E. Frontal cortex contributes to human memory formation. Nature Neurosci. 2, 311–314 (1999).

    Article  CAS  Google Scholar 

  22. Fink, G. R.et al. Cerebral representation of one's own past: neural networks involved in autobiographical memory. J. Neurosci. 16, 4275–4282 (1996).

    Article  CAS  Google Scholar 

  23. Ungerleider, L. G. Functional brain imaging studies of cortical mechanisms for memory. Science 270, 769–775 (1995).

    Article  CAS  ADS  Google Scholar 

  24. Schacter, D. L., Alpert, N. M., Savage, C. R., Rauch, S. L. & Albert, M. S. Conscious recollection and the human hippocampal formation: evidence from positron emission tomography. Proc. Natl Acad. Sci. USA 93, 321–325 (1996).

    Article  CAS  ADS  Google Scholar 

  25. Gabrieli, J. D. E. Cognitive neuroscience of human memory. Annu. Rev. Psychol. 49, 87–115 (1998).

    Article  CAS  Google Scholar 

  26. Alkire, M. T., Haier, R. J., Fallon, J. H. & Cahill, L. Hippocampal, but not amygdala, activity at encoding correlates with long-term, free recall of nonemotional information. Proc. Natl Acad. Sci. USA 95, 14506–14510 (1998).

    Article  CAS  ADS  Google Scholar 

  27. Buzsaki, G. Memory consolidation during sleep: a neuropsychological perspective. J. Sleep Res. 7, 17–23 (1998).

    Article  Google Scholar 

  28. Lehman, A. Atlas Stéréotaxique du Cerveau de la Souris (Editions du CNRS, Paris, 1974).

    Google Scholar 

  29. McIntosh, A. R. & Gonzalez-Lima, F. Network interactions among limbic cortices, basal forebrain and cerebellum differentiate a tone conditioned as a Pavlovian excitor or inhibitor: fluorodeoxyglucose mapping and covariance structural modelling. J. Neurophysiol. 72, 1717–1733 (1994).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank T. Durkin, B. Poucet and Y. H. Cho for comments on earlier drafts of the manuscript. This work was funded by grants from the CNRS and the Université Bordeaux I.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Bruno Bontempi.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bontempi, B., Laurent-Demir, C., Destrade, C. et al. Time-dependent reorganization of brain circuitry underlying long-term memory storage. Nature 400, 671–675 (1999). https://doi.org/10.1038/23270

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/23270

This article is cited by

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.

Search

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