Reactivation of Hippocampal Cell Assemblies: Effects of Behavioral State, Experience, and EEG Dynamics

  title={Reactivation of Hippocampal Cell Assemblies: Effects of Behavioral State, Experience, and EEG Dynamics},
  author={Hemant S. Kudrimoti and Carol A. Barnes and Bruce L. McNaughton},
  journal={The Journal of Neuroscience},
  pages={4090 - 4101}
During slow wave sleep (SWS), traces of neuronal activity patterns from preceding behavior can be observed in rat hippocampus and neocortex. The spontaneous reactivation of these patterns is manifested as the reinstatement of the distribution of pairwise firing-rate correlations within a population of simultaneously recorded neurons. The effects of behavioral state [quiet wakefulness, SWS, and rapid eye movement (REM)], interactions between two successive spatial experiences, and global… 
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.
Long-Lasting Novelty-Induced Neuronal Reverberation during Slow-Wave Sleep in Multiple Forebrain Areas
The results indicate that persistent experience-dependent neuronal reverberation is a general property of multiple forebrain structures, and does not consist of an exact replay of previous activity, but instead it defines a mild and consistent bias towards salient neural ensemble firing patterns.
Learning-induced sequence reactivation during sharp-wave ripples: a computational study
The model of SWR activity revealed that the recently learned trajectory reactivates during sleep more often than other trajectories in the training field, and predicted that the gain of reactivation rate during sleep following vs sleep preceding learning for a trained sequence of pyramidal cells depends on Pre-sleep activation of the same sequence, and on the amount of trajectory repetitions included in theTraining phase.
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
Mnemonic information in the rodent hippocampus during wake and sleep states
Results show that information regarding behavioral salience can reach the hippocampus, and becomes incorporated into a broad hippocampal representation of experience, and provides a basis for the electrophysiological examination of mnemonic content in sleep and dream states.
Hippocampal–cortical interaction during periods of subcortical silence
These findings suggest that during off-line memory consolidation, synergistic thalamocortical activity may be orchestrating a privileged interaction state between hippocampus and cortex by silencing the output of subcortical centres involved in sensory processing or potentially mediating procedural learning.
Bidirectional Interaction of Hippocampal Ripples and Cortical Slow Waves Leads to Coordinated Spiking Activity During NREM Sleep.
The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.
Synchronous Bursts of Neuronal Activity in the Developing Hippocampus: Modulation by Active Sleep and Association with Emerging Gamma and Theta Rhythms
It is hypothesized that the phasic motor events of active sleep provide the developing hippocampus with discrete sensory stimulation that contributes to the development and refinement of hippocampal circuits as well as the development of synchronized interactions between hippocampus and neocortex.
Offline reactivation of experience-dependent neuronal firing patterns in the rat ventral tegmental area.
It is provided new evidence that rodent ventral tegmental area (VTA) neurons are selective for different types of food stimuli and that stimulus-sensitive neurons strongly reactivate during the rest period following a task that involved those stimuli.


Reactivation of hippocampal ensemble memories during sleep.
Recordings from large ensembles of hippocampal "place cells" in three rats showed that 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.
Memory reprocessing in corticocortical and hippocampocortical neuronal ensembles.
Hippocampal cells that fire together during behaviour exhibit enhanced activity correlations during subsequent sleep, with some preservation of temporal order information, and traces of recent experience are re-expressed in both hippocampal and neocortical circuits during sleep.
Memory consolidation during sleep: a neurophysiological perspective.
It is suggested that sleep patterns in the limbic system are essential for the preservation of experience-induced synaptic modifications, and the subcortical effects of hippocampal sharp wave bursts may be critical in the release of various hormones which, in turn, may affect synaptic plasticity.
Hippocampal Rhythmic Slow Activity and Neocortical Low-Voltage Fast Activity: Relations to Behavior
The data summarized here will show that details of actual behavior are important in the study of brain and behavior, and merit careful observation and precise description.
High-Frequency Oscillations in the Output Networks of the Hippocampal–Entorhinal Axis of the Freely Behaving Rat
There is a powerful synchronization among the neuronal networks that connect the hippocampus to the neocortex during each hippocampal sharp wave, which biologically constrains theoretical models of hippocampal function and dysfunction and has the capacity to support an “off-line” memory consolidation process.
Selective activation of deep layer (V-VI) retrohippocampal cortical neurons during hippocampal sharp waves in the behaving rat
  • JJ Chrobak, G. Buzsáki
  • Biology, Psychology
    The Journal of neuroscience : the official journal of the Society for Neuroscience
  • 1994
It is suggested that SPW-associated population bursts in hippocampal and retrohippocampal cortices exert a powerful depolarizing effect on their postsynaptic neocortical targets and may represent a physiological mechanism for memory trace transfer from the hippocampus to the neocortex.
Replay of Neuronal Firing Sequences in Rat Hippocampus During Sleep Following Spatial Experience
The correlated activity of rat hippocampal pyramidal cells during sleep reflects the activity of those cells during earlier spatial exploration and this memory for temporal order of neuronal firing could be produced by an interaction between the temporal integration properties of long-term potentiation and the phase shifting of spike activity with respect to the hippocampal theta rhythm.
Phase relationship between hippocampal place units and the EEG theta rhythm
The phase was highly correlated with spatial location and less well correlated with temporal aspects of behavior, such as the time after place field entry, and the characteristics of the phase shift constrain the models that define the construction of place fields.