Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples
Summary: Hippocampal sharp-wave ripples (SPW-Rs) support consolidation of recently acquired episodic memories and planning future actions by generating ordered neuronal sequences of previous or future experiences. SPW-Rs are characterized by several spectral components: a slow (5–15 Hz) sharp-wave,...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2018-11-01
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| Series: | Cell Reports |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S221112471831670X |
| _version_ | 1818482965889417216 |
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| author | Azahara Oliva Antonio Fernández-Ruiz Eliezyer Fermino de Oliveira György Buzsáki |
| author_facet | Azahara Oliva Antonio Fernández-Ruiz Eliezyer Fermino de Oliveira György Buzsáki |
| author_sort | Azahara Oliva |
| collection | DOAJ |
| description | Summary: Hippocampal sharp-wave ripples (SPW-Rs) support consolidation of recently acquired episodic memories and planning future actions by generating ordered neuronal sequences of previous or future experiences. SPW-Rs are characterized by several spectral components: a slow (5–15 Hz) sharp-wave, a high-frequency “ripple” oscillation (150–200 Hz), and a slow “gamma” oscillation (20–40 Hz). Using laminar hippocampal recordings and optogenetic manipulations, we dissected the origin of these spectral components. We show that increased power in the 20–40 Hz band does not reflect an entrainment of CA1 and CA3 neurons at gamma frequency but the power envelope of overlapping ripples. Spike-local field potential coupling between unit firing in CA1 and CA3 regions during SPW-Rs is lowest in the gamma band. Longer SPW-Rs are preceded by increased firing in the entorhinal cortex. Thus, fusion of SPW-Rs leads to lengthening of their duration associated with increased power in the slow gamma band without the presence of true oscillation. : SWRs are thought to support memory consolidation and planning. They are characterized by several spectral components: a slow-frequency wave (sharp-wave), a high-frequency oscillation (ripple), and a slow “gamma” band. Here, we report a mechanism, involving the concatenation of several SWRs, which explains the generation of the “gamma” frequency band. Keywords: hippocampus, oscillations, memory consolidation, sharp-wave ripples, gamma, entorhinal cortex, optogenetics |
| first_indexed | 2024-12-10T11:54:01Z |
| format | Article |
| id | doaj.art-9b2a439d04284f11bef1e90dae9ea35e |
| institution | Directory Open Access Journal |
| issn | 2211-1247 |
| language | English |
| last_indexed | 2024-12-10T11:54:01Z |
| publishDate | 2018-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Cell Reports |
| spelling | doaj.art-9b2a439d04284f11bef1e90dae9ea35e2022-12-22T01:49:51ZengElsevierCell Reports2211-12472018-11-0125716931700.e4Origin of Gamma Frequency Power during Hippocampal Sharp-Wave RipplesAzahara Oliva0Antonio Fernández-Ruiz1Eliezyer Fermino de Oliveira2György Buzsáki3New York University Neuroscience Institute, New York, NY 10016, USA; Department of Neuroscience, Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USANew York University Neuroscience Institute, New York, NY 10016, USANew York University Neuroscience Institute, New York, NY 10016, USA; Center for Mathematics, Computing and Cognition, Universidade Federal do ABC, São Bernardo do Campo, São Paulo, BrazilNew York University Neuroscience Institute, New York, NY 10016, USA; Center for Neural Science, New York University, New York, NY 10016, USA; Corresponding authorSummary: Hippocampal sharp-wave ripples (SPW-Rs) support consolidation of recently acquired episodic memories and planning future actions by generating ordered neuronal sequences of previous or future experiences. SPW-Rs are characterized by several spectral components: a slow (5–15 Hz) sharp-wave, a high-frequency “ripple” oscillation (150–200 Hz), and a slow “gamma” oscillation (20–40 Hz). Using laminar hippocampal recordings and optogenetic manipulations, we dissected the origin of these spectral components. We show that increased power in the 20–40 Hz band does not reflect an entrainment of CA1 and CA3 neurons at gamma frequency but the power envelope of overlapping ripples. Spike-local field potential coupling between unit firing in CA1 and CA3 regions during SPW-Rs is lowest in the gamma band. Longer SPW-Rs are preceded by increased firing in the entorhinal cortex. Thus, fusion of SPW-Rs leads to lengthening of their duration associated with increased power in the slow gamma band without the presence of true oscillation. : SWRs are thought to support memory consolidation and planning. They are characterized by several spectral components: a slow-frequency wave (sharp-wave), a high-frequency oscillation (ripple), and a slow “gamma” band. Here, we report a mechanism, involving the concatenation of several SWRs, which explains the generation of the “gamma” frequency band. Keywords: hippocampus, oscillations, memory consolidation, sharp-wave ripples, gamma, entorhinal cortex, optogeneticshttp://www.sciencedirect.com/science/article/pii/S221112471831670X |
| spellingShingle | Azahara Oliva Antonio Fernández-Ruiz Eliezyer Fermino de Oliveira György Buzsáki Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples Cell Reports |
| title | Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples |
| title_full | Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples |
| title_fullStr | Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples |
| title_full_unstemmed | Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples |
| title_short | Origin of Gamma Frequency Power during Hippocampal Sharp-Wave Ripples |
| title_sort | origin of gamma frequency power during hippocampal sharp wave ripples |
| url | http://www.sciencedirect.com/science/article/pii/S221112471831670X |
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