Hippocampal theta rhythm: A tag for short‐term memory

@article{Vertes2005HippocampalTR,
  title={Hippocampal theta rhythm: A tag for short‐term memory},
  author={Robert P. Vertes},
  journal={Hippocampus},
  year={2005},
  volume={15}
}
  • R. Vertes
  • Published 2005
  • Psychology, Medicine
  • Hippocampus
The theta rhythm is the largest extracellular synchronous signal that can be recorded from the mammalian brain, and has been strongly implicated in mnemonic functions of the hippocampus. We advance the proposal that the theta rhythm represents a “tag” for short‐term memory processing in the hippocampus. We propose that the hippocampus receives two main types of input, theta from ascending brainstem‐diencephalo‐septal systems and “information bearing” mainly from thalamocortical and cortical… Expand
Human hippocampal theta oscillations and the formation of episodic memories
TLDR
Recorded intracranial EEG data from 237 hippocampal electrodes in 33 neurosurgical patients as they performed an episodic memory task identified two distinct patterns of hippocampal oscillations, at ∼3 and ∼8 Hz, which are at the edges of the traditional 4–8 Hz human theta band. Expand
The Theta Rhythm of the Hippocampus: From Neuronal and Circuit Mechanisms to Behavior
TLDR
This review focuses on the neuronal and circuit mechanisms involved in the generation of the theta (θ) rhythm and of its participation in behavior and discusses that the loss of this interaction is at the base of various neurophatological conditions. Expand
Relationship of Hippocampal Theta and Gamma Oscillations to Potentiation of Synaptic Transmission
TLDR
Findings are discussed in the context of possible mechanisms that link theta and gamma oscillations with LTP induction, as well as their role in information processing and formation of memories. Expand
Hippocampal Network Activity is Transiently Altered by Induction of Long-Term Potentiation in the Dentate Gyrus of Freely Behaving Rats
TLDR
The data support that specific, correlated changes in these parameters are associated with successful synaptic potentiation and suggest that changes in theta-gamma activity associated with induction of LTP may enable synaptic information storage in the hippocampus. Expand
Regular theta‐firing neurons in the nucleus incertus during sustained hippocampal activation
TLDR
The present work analyses the neuronal activity in the NI in conditions leading to sustained hippocampal theta in the urethane‐anaesthetised rat, in order to test whether such activation elicits a differential firing pattern. Expand
Modulation of hippocampal neuronal network oscillations by α7 nACh receptors.
TLDR
It is hypothesize that increases in theta power and theta-phase gamma-amplitude coupling due to α7 nAChR agonists during elicited hippocampal oscillations could reflect changes in synchronous activity of pyramidal neurons which is a critical factor for hippocampal-dependent cognitive function. Expand
Global rhythmic activities in hippocampal neural fields and neural coding.
TLDR
A model of oscillatory activities of the CA3 field in theta range has been formulated, showing that the propagation of activities induced in the neural field by hippocampal afferents occurs only in narrow time windows confined by inhibitory barrages, whose time-course follows the theta rhythm. Expand
Analysis of the Actions of Nucleus Reuniens and the Entorhinal Cortex on EEG and Evoked Population Behavior of the Hippocampus
TLDR
The present data suggests an increase in RE spike rate due to tail pinch elicited theta activity, with no evidence of bursting activity and a weak coherence within the theta band. Expand
Modulation of hippocampal theta oscillations and spatial memory by relaxin-3 neurons of the nucleus incertus.
TLDR
In anesthetized and conscious rats, the ability of intraseptal RLN3 signaling to modulate neuronal activity in the MS and hippocampus and promote hippocampal theta rhythm was identified and the effects observed could be an important component of memory processing associated with stress responses. Expand
Hippocampal theta-dependent eyeblink classical conditioning: Coordination of a distributed learning system
TLDR
Hippocampal and cerebellar local field potentials show that these distantly interconnected brain structures become precisely synchronized when conditions favor rapid behavioral acquisition and suggest a major role for theta in coordinating the widely distributed memory system for trace EBCC. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 135 REFERENCES
Intrinsic oscillations in CA3 hippocampal pyramids: Physiological relevance to theta rhythm generation
TLDR
It is shown that hippocampal neurons, recorded from juvenile and adult slices, are endowed with intrinsic properties that allow the generation of a steady oscillatory activity, and regularly occurring membrane potential oscillations can be detected since postnatal day 10 and their frequency increases with age, i.e., during the following 2 weeks. Expand
Theta rhythm of the hippocampus: subcortical control and functional significance.
TLDR
It is suggested that the hippocampus receives two main types of input: theta rhythm from ascending brain stem- diencephaloseptal systems and information bearing mainly from thalamocortical/cortical systems. Expand
The Role of Theta-Range Oscillations in Synchronising and Integrating Activity in Distributed Mnemonic Networks
TLDR
It will be argued that theta-rhythmic activity occurs across distributed networks within the diencephalon and neocortex as well as the hippocampus, and functions to temporally coordinate activity in distributed systems within these regions during mnemonic processes. Expand
Theta reset produces optimal conditions for long‐term potentiation
TLDR
The hypothesis that resetting of local hippocampal theta to relevant stimuli in a working memory task produces optimal conditions for induction of LTP is investigated and results suggest that a memory‐relevant stimulus produces a phase shift of ongoing theta rhythm that induces optimal conditions to undergo potentiation. Expand
A Proposed Function for Hippocampal Theta Rhythm: Separate Phases of Encoding and Retrieval Enhance Reversal of Prior Learning
TLDR
A hippocampal model shows how theta rhythm could be important for reversal in this task by providing separate functional phases during each 100-300 msec cycle, consistent with physiological data. Expand
Brainstem-diencephalo-septohippocampal systems controlling the theta rhythm of the hippocampus.
TLDR
It is demonstrated that the theta rhythm is controlled by a network of cells extending from the brainstem to the septum/hippocampus and that its disruption (electroencephalographic desynchronization) may block or temporarily suspend mnemonic processes of the hippocampus. Expand
INTRACELLULAR RECORDS FROM HIPPOCAMPAL PYRAMIDAL CELLS IN RABBIT DURING THETA RHYTHM ACTIVITY.
TLDR
The theta rhythm usually exists in unanesthetized animals and becomes prominent after various kinds of afferent stimulation or after stimulation of the midbrain reticular formation, and in this descriptive sense the hippocampal EEG bears an inverse relationship to the neocortical EEG. Expand
Rhinal–hippocampal theta coherence during declarative memory formation: interaction with gamma synchronization?
TLDR
While theta coherence might be associated with slowly modulated coupling related to an encoding state, rhinal–hippocampal gamma synchronization may be more closely related to actual memory processes by enabling fast coupling and decoupling of the two structures. Expand
Theta oscillations in somata and dendrites of hippocampal pyramidal cells in vivo: Activity‐dependent phase‐precession of action potentials
TLDR
Data indicate that distal dendritic depolarization of the pyramidal cell by the entorhinal input during theta overlaps in time with somatic hyperpolarization, and hypothesize that the competition between the out‐of‐phase theta oscillation in the soma and dendrite is responsible for the advancement of spike discharges observed in the behaving animal. Expand
Event-Induced Theta Responses as a Window on the Dynamics of Memory
TLDR
The experimental evidence largely supports the hypothesis that theta activity plays a functional role in cell assembly formation, a process which may constitute the neural basis of memory formation and retrieval. Expand
...
1
2
3
4
5
...