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Open AccessJournal ArticleDOI

Hippocampal sharp wave‐ripple: A cognitive biomarker for episodic memory and planning

György Buzsáki
- 01 Oct 2015 - 
- Vol. 25, Iss: 10, pp 1073-1188
TLDR
Alteration of the physiological mechanisms supporting SPW‐Rs leads to their pathological conversion, “p‐ripples,” which are a marker of epileptogenic tissue and can be observed in rodent models of schizophrenia and Alzheimer's Disease.
Abstract
Sharp wave ripples (SPW-Rs) represent the most synchronous population pattern in the mammalian brain. Their excitatory output affects a wide area of the cortex and several subcortical nuclei. SPW-Rs occur during "off-line" states of the brain, associated with consummatory behaviors and non-REM sleep, and are influenced by numerous neurotransmitters and neuromodulators. They arise from the excitatory recurrent system of the CA3 region and the SPW-induced excitation brings about a fast network oscillation (ripple) in CA1. The spike content of SPW-Rs is temporally and spatially coordinated by a consortium of interneurons to replay fragments of waking neuronal sequences in a compressed format. SPW-Rs assist in transferring this compressed hippocampal representation to distributed circuits to support memory consolidation; selective disruption of SPW-Rs interferes with memory. Recently acquired and pre-existing information are combined during SPW-R replay to influence decisions, plan actions and, potentially, allow for creative thoughts. In addition to the widely studied contribution to memory, SPW-Rs may also affect endocrine function via activation of hypothalamic circuits. Alteration of the physiological mechanisms supporting SPW-Rs leads to their pathological conversion, "p-ripples," which are a marker of epileptogenic tissue and can be observed in rodent models of schizophrenia and Alzheimer's Disease. Mechanisms for SPW-R genesis and function are discussed in this review.

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Rhythms of the hippocampal network

TL;DR: The current understanding of the origins and the mnemonic functions of hippocampal theta, sharp wave–ripples and gamma rhythms is discussed on the basis of findings from rodent studies and an updated synthesis of their roles and interactions within the hippocampal network is presented.
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Mechanisms of systems memory consolidation during sleep.

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Elements Of Episodic Memory

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Memory engrams: Recalling the past and imagining the future

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References
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Journal ArticleDOI

Learning representations by back-propagating errors

TL;DR: Back-propagation repeatedly adjusts the weights of the connections in the network so as to minimize a measure of the difference between the actual output vector of the net and the desired output vector, which helps to represent important features of the task domain.
Journal ArticleDOI

Neural networks and physical systems with emergent collective computational abilities

TL;DR: A model of a system having a large number of simple equivalent components, based on aspects of neurobiology but readily adapted to integrated circuits, produces a content-addressable memory which correctly yields an entire memory from any subpart of sufficient size.
Journal ArticleDOI

A synaptic model of memory: long-term potentiation in the hippocampus

TL;DR: The best understood form of long-term potentiation is induced by the activation of the N-methyl-d-aspartate receptor complex, which allows electrical events at the postsynaptic membrane to be transduced into chemical signals which, in turn, are thought to activate both pre- and post Synaptic mechanisms to generate a persistent increase in synaptic strength.
Journal ArticleDOI

A default mode of brain function.

TL;DR: A baseline state of the normal adult human brain in terms of the brain oxygen extraction fraction or OEF is identified, suggesting the existence of an organized, baseline default mode of brain function that is suspended during specific goal-directed behaviors.
Book

The Hippocampus as a Cognitive Map

John O'Keefe, +1 more
TL;DR: The amnesic syndrome is presented as an extension of the theory to humans and the role of operators in the locale system is examined.
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