Abstract
Some forms of memory have been shown to depend on a system of medial temporal lobe structures that includes the hippocampus and the adjacent cortical areas (entorhinal, perirhinal, and parahippocampal cortex). The role of this system is only temporary, however, as indicated by the fact that, after damage to the medial temporal lobe, recent memories are impaired but very remote memories are intact. Here we review the evidence that the medial temporal lobe memory system is involved in a process of consolidation: memories are initially dependent on this system but gradually become established in other areas of the brain. We then review some of the ideas that have been proposed about the phenomenon of consolidation and suggest a synthesis of these views. Finally, we describe a simple neural network model that captures some key features of consolidation.
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- Buzsáki G., Horváth Z., Urioste R., Hetke J., Wise K. High-frequency network oscillation in the hippocampus. Science. 1992 May 15;256(5059):1025–1027. doi: 10.1126/science.1589772. [DOI] [PubMed] [Google Scholar]
- 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. 1993 Apr;13(4):1759–1766. doi: 10.1523/JNEUROSCI.13-04-01759.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Damasio A. R. Time-locked multiregional retroactivation: a systems-level proposal for the neural substrates of recall and recognition. Cognition. 1989 Nov;33(1-2):25–62. doi: 10.1016/0010-0277(89)90005-x. [DOI] [PubMed] [Google Scholar]
- Gluck M. A., Myers C. E. Hippocampal mediation of stimulus representation: a computational theory. Hippocampus. 1993 Oct;3(4):491–516. doi: 10.1002/hipo.450030410. [DOI] [PubMed] [Google Scholar]
- Grossberg S. Adaptive pattern classification and universal recoding: I. Parallel development and coding of neural feature detectors. Biol Cybern. 1976 Jul 30;23(3):121–134. doi: 10.1007/BF00344744. [DOI] [PubMed] [Google Scholar]
- Kim J. J., Fanselow M. S. Modality-specific retrograde amnesia of fear. Science. 1992 May 1;256(5057):675–677. doi: 10.1126/science.1585183. [DOI] [PubMed] [Google Scholar]
- Marr D. Simple memory: a theory for archicortex. Philos Trans R Soc Lond B Biol Sci. 1971 Jul 1;262(841):23–81. doi: 10.1098/rstb.1971.0078. [DOI] [PubMed] [Google Scholar]
- Milner P. M. A cell assembly theory of hippocampal amnesia. Neuropsychologia. 1989;27(1):23–30. doi: 10.1016/0028-3932(89)90087-0. [DOI] [PubMed] [Google Scholar]
- SCOVILLE W. B., MILNER B. Loss of recent memory after bilateral hippocampal lesions. J Neurol Neurosurg Psychiatry. 1957 Feb;20(1):11–21. doi: 10.1136/jnnp.20.1.11. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Squire L. R. Memory and the hippocampus: a synthesis from findings with rats, monkeys, and humans. Psychol Rev. 1992 Apr;99(2):195–231. doi: 10.1037/0033-295x.99.2.195. [DOI] [PubMed] [Google Scholar]
- Squire L. R., Slater P. C., Chace P. M. Retrograde amnesia: temporal gradient in very long term memory following electroconvulsive therapy. Science. 1975 Jan 10;187(4171):77–79. doi: 10.1126/science.1109228. [DOI] [PubMed] [Google Scholar]
- Squire L. R., Spanis C. W. Long gradient of retrograde amnesia in mice: continuity with the findings in humans. Behav Neurosci. 1984 Apr;98(2):345–348. doi: 10.1037//0735-7044.98.2.345. [DOI] [PubMed] [Google Scholar]
- Squire L. R., Zola-Morgan S. The medial temporal lobe memory system. Science. 1991 Sep 20;253(5026):1380–1386. doi: 10.1126/science.1896849. [DOI] [PubMed] [Google Scholar]
- Teyler T. J., DiScenna P. The hippocampal memory indexing theory. Behav Neurosci. 1986 Apr;100(2):147–154. doi: 10.1037//0735-7044.100.2.147. [DOI] [PubMed] [Google Scholar]
- Wickelgren W. A. Chunking and consolidation: a theoretical synthesis of semantic networks, configuring in conditioning, S--R versus congenitive learning, normal forgetting, the amnesic syndrome, and the hippocampal arousal system. Psychol Rev. 1979 Jan;86(1):44–60. [PubMed] [Google Scholar]
- Winocur G. Anterograde and retrograde amnesia in rats with dorsal hippocampal or dorsomedial thalamic lesions. Behav Brain Res. 1990 May 7;38(2):145–154. doi: 10.1016/0166-4328(90)90012-4. [DOI] [PubMed] [Google Scholar]
- Zola-Morgan S. M., Squire L. R. The primate hippocampal formation: evidence for a time-limited role in memory storage. Science. 1990 Oct 12;250(4978):288–290. doi: 10.1126/science.2218534. [DOI] [PubMed] [Google Scholar]