| Reference code: | PT/FB/BL-2004-168.05 |
| Location: | Arquivo PCA - Pasta 13/2004
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Title:
| Temporal coupling of parahippocampal ripples and sleep spindles in humans
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| Publication year: | 2006
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URL:
| http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2869.2006.00540_57.x/pdf
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| Abstract/Results: | ABSTRACT:
Ripples are high-frequency oscillation bursts in the mammalian hippocampus mainly present during NREM sleep. In rodents they occur in association with sharp waves and are known to be grouped by the cortical slow oscillation such that their occurrence is maximal during the surface positive, up states. Ripples were also shown to be temporally linked to sleep spindles. Importantly, coordinated spindleripple events have been suggested to provide a framework for information transfer between the hippocampus and the neocortex underlying memory consolidation. Our aim was to examine whether ripples recorded via parahippocampal electrocorticography are also temporally linked with slow oscillations and sleep spindles in epileptic
humans. Whole-night recordings from seven epilepsy patients implanted with foramen ovale (FO) electrodes were analysed. Negative half waves of the slow oscillation and sleep spindles recorded on the scalp as well as ripples in FO recordings were detected by an automatic algorithm. Ripple activity was also measured as root mean square (RMS) of the 80–140 Hz activity. Compared to baseline both ripple measures showed a significant increase time-locked to sleep spindles. In the three patients without temporal structural alterations ripple activity decreased time-locked to slow oscillation negative half waves. In the four other patients exhibiting hippocampal sclerosis, modulation of ripple activity by the negative half waves was much less clear. Ripples significantly increased during NREM sleep and were consistently associated with interictal epileptic spikes. This suggests that ripple/spike complexes represent an epileptic exaggeration of ripple/sharp wave complexes in the human epileptic hippocampus. Whether ripples are epileptically transformed or not, the present data provide first evidence for a temporal coupling between hippocampal ripples and neocortical spindles in humans.
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| Accessibility: | Document does not exist in file
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Language:
| eng
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Author:
| Clemens, Z.
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Secondary author(s):
| Mölle, M., Eröss, L., Barsi, P., Halász, P., Born, J.
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Document type:
| Abstract
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Number of reproductions:
| 1
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Reference:
| Clemens, Z., Molle, M., Eross, L., Barsi, P., Halasz, P., & Born, J. (2006). Temporal coupling of parahippocampal ripples and sleep spindles in humans. Journal of Sleep Research, 15(Suppl. 1), 242-242. https://doi.org/10.1111/j.1365-2869.2006.00540_57.x
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| Indexed document: | Yes
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| Keywords: | Sleep / Hippocampus / Sharp-wave ripples / Epilepsy
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Temporal coupling of parahippocampal ripples and sleep spindles in humans |