Reactivation of hippocampal ensemble memories during sleep.

  title={Reactivation of hippocampal ensemble memories during sleep.},
  author={M. Alice Wilson and Bruce L. McNaughton},
  volume={265 5172},
Simultaneous recordings were made from large ensembles of hippocampal "place cells" in three rats during spatial behavioral tasks and in slow-wave sleep preceding and following these behaviors. Cells that fired together when the animal occupied particular locations in the environment exhibited an increased tendency to fire together during subsequent sleep, in comparison to sleep episodes preceding the behavioral tasks. Cells that were inactive during behavior, or that were active but had non… 
Are Spatial Memories Strengthened in the Human Hippocampus during Slow Wave Sleep?
Reactivation of neuronal ensembles in hippocampal dentate gyrus during sleep after spatial experience
Whether ensemble firing patterns of granule cells in the fascia dentata (FD), an area ‘upstream’ from CA3, are also reactivated during sleep is investigated to extend the understanding of the generality of this phenomenon.
Reactivation of hippocampal ensemble activity patterns in the aging rat.
Age differences in spatial memory do not appear to be explainable by differences in the spontaneous reactivation of familiar patterns within the hippocampus during the immediate postbehavior period.
Memory of Sequential Experience in the Hippocampus during Slow Wave Sleep
Hippocampal Sharp Waves and Reactivation during Awake States Depend on Repeated Sequential Experience
Hippocampal firing patterns during behavior are reactivated during rest and subsequent slow-wave sleep. These reactivations occur during transient local field potential (LFP) events, termed sharp
Reactivation of Hippocampal Cell Assemblies: Effects of Behavioral State, Experience, and EEG Dynamics
Pattern reinstatement was strongest during sharp wave–ripple oscillations, suggesting that these events may reflect system convergence onto attractor states corresponding to previous experiences, and do not necessarily reflect persistence of an active memory.
Firing rates of hippocampal neurons are preserved during subsequent sleep episodes and modified by novel awake experience
In a familiar environment, the discharge frequency of simultaneously recorded individual CA1 pyramidal neurons and the coactivation of cell pairs remain highly correlated across sleep–wake–sleep sequences, but both measures were affected when new sets of neurons were activated in a novel environment.
Coordinated memory replay in the visual cortex and hippocampus during sleep
It is found that spiking patterns not only in the cortex but also in the hippocampus were organized into frames, defined as periods of stepwise increase in neuronal population activity.
Reactivation of behavioral activity during sharp waves: A computational model for two stage hippocampal dynamics
It is demonstrated here that patterns of reactivation can be successfully reproduced by relying on a computational model of the hippocampus with theta phase precession and synaptic plasticity during theta rhythm to initiate SPWs events.
Hippocampal ripples and memory consolidation


Dependence of cortical plasticity on correlated activity of single neurons and on behavioral context.
The results indicate that changes in the temporal contingency between neurons are often necessary, but not sufficient, for cortical plasticity in the adult monkey: behavioral relevance is required.
Dynamics of the hippocampal ensemble code for space.
Parallel recording methods outlined here make possible the study of the dynamics of neuronal interactions during unique behavioral events, which suggests that new spatial information creates conditions in the hippocampal circuitry that are conducive to the synaptic modification presumed to be involved in learning.
Hippocampal electrical activity and voluntary movement in the rat.
  • C. H. Vanderwolf
  • Biology, Psychology
    Electroencephalography and clinical neurophysiology
  • 1969
Modality-specific retrograde amnesia of fear.
The results indicate that fear memory is not a single process and that the hippocampus may have a time-limited role in associative fear memories evoked by polymodal (contextual) but not unimodal (tone) sensory stimuli.
Hippocampal synaptic plasticity and NMDA receptors: a role in information storage?
Two new studies are described whose results show that AP5 has no effect upon the retrieval of previously established memories, and that the dose-response profile of the impairment of spatial learning occurs across a range of extracellular concentrations in hippocampus for which receptor selectivity exists.
An age comparison of the rates of acquisition and forgetting of spatial information in relation to long-term enhancement of hippocampal synapses.
Although the absolute rates of behavioral acquisition and forgetting were different from the corresponding rates of increase and decay of LTE, the relative differences between age groups were rather similar and the relation of these data to the hypothesis that LTE underlies spatial learning and memory is discussed.
Long-term potentiation.
The available evidence suggests that L TP does occur in conjunction with behavioral learning-although whether it is necessary and sufficient is far from certain.