Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes.
Brain recovery after prolonged wakefulness is characterized by increased density, amplitude and slope of slow waves (SW, <4 Hz) during non-rapid eye movement (NREM) sleep. These SW comprise a negative phase, during which cortical neurons are mostly silent, and a positive phase, in which most neur...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2011-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3150370?pdf=render |
| _version_ | 1818262406234636288 |
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| author | Valérie Mongrain Julie Carrier Jean Paquet Erika Bélanger-Nelson Marie Dumont |
| author_facet | Valérie Mongrain Julie Carrier Jean Paquet Erika Bélanger-Nelson Marie Dumont |
| author_sort | Valérie Mongrain |
| collection | DOAJ |
| description | Brain recovery after prolonged wakefulness is characterized by increased density, amplitude and slope of slow waves (SW, <4 Hz) during non-rapid eye movement (NREM) sleep. These SW comprise a negative phase, during which cortical neurons are mostly silent, and a positive phase, in which most neurons fire intensively. Previous work showed, using EEG spectral analysis as an index of cortical synchrony, that Morning-types (M-types) present faster dynamics of sleep pressure than Evening-types (E-types). We thus hypothesized that single SW properties will also show larger changes in M-types than in E-types in response to increased sleep pressure. SW density (number per minute) and characteristics (amplitude, slope between negative and positive peaks, frequency and duration of negative and positive phases) were compared between chronotypes for a baseline sleep episode (BL) and for recovery sleep (REC) after two nights of sleep fragmentation. While SW density did not differ between chronotypes, M-types showed higher SW amplitude and steeper slope than E-types, especially during REC. SW properties were also averaged for 3 NREM sleep periods selected for their decreasing level of sleep pressure (first cycle of REC [REC1], first cycle of BL [BL1] and fourth cycle of BL [BL4]). Slope was significantly steeper in M-types than in E-types in REC1 and BL1. SW frequency was consistently higher and duration of positive and negative phases constantly shorter in M-types than in E-types. Our data reveal that specific properties of cortical synchrony during sleep differ between M-types and E-types, although chronotypes show a similar capacity to generate SW. These differences may involve 1) stable trait characteristics independent of sleep pressure (i.e., frequency and durations) likely linked to the length of silent and burst-firing phases of individual neurons, and 2) specific responses to increased sleep pressure (i.e., slope and amplitude) expected to depend on the synchrony between neurons. |
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| format | Article |
| id | doaj.art-51a2ea6d12d541d9975d9ee58177fc17 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-12T19:02:37Z |
| publishDate | 2011-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-51a2ea6d12d541d9975d9ee58177fc172022-12-22T00:15:03ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0168e2267910.1371/journal.pone.0022679Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes.Valérie MongrainJulie CarrierJean PaquetErika Bélanger-NelsonMarie DumontBrain recovery after prolonged wakefulness is characterized by increased density, amplitude and slope of slow waves (SW, <4 Hz) during non-rapid eye movement (NREM) sleep. These SW comprise a negative phase, during which cortical neurons are mostly silent, and a positive phase, in which most neurons fire intensively. Previous work showed, using EEG spectral analysis as an index of cortical synchrony, that Morning-types (M-types) present faster dynamics of sleep pressure than Evening-types (E-types). We thus hypothesized that single SW properties will also show larger changes in M-types than in E-types in response to increased sleep pressure. SW density (number per minute) and characteristics (amplitude, slope between negative and positive peaks, frequency and duration of negative and positive phases) were compared between chronotypes for a baseline sleep episode (BL) and for recovery sleep (REC) after two nights of sleep fragmentation. While SW density did not differ between chronotypes, M-types showed higher SW amplitude and steeper slope than E-types, especially during REC. SW properties were also averaged for 3 NREM sleep periods selected for their decreasing level of sleep pressure (first cycle of REC [REC1], first cycle of BL [BL1] and fourth cycle of BL [BL4]). Slope was significantly steeper in M-types than in E-types in REC1 and BL1. SW frequency was consistently higher and duration of positive and negative phases constantly shorter in M-types than in E-types. Our data reveal that specific properties of cortical synchrony during sleep differ between M-types and E-types, although chronotypes show a similar capacity to generate SW. These differences may involve 1) stable trait characteristics independent of sleep pressure (i.e., frequency and durations) likely linked to the length of silent and burst-firing phases of individual neurons, and 2) specific responses to increased sleep pressure (i.e., slope and amplitude) expected to depend on the synchrony between neurons.http://europepmc.org/articles/PMC3150370?pdf=render |
| spellingShingle | Valérie Mongrain Julie Carrier Jean Paquet Erika Bélanger-Nelson Marie Dumont Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. PLoS ONE |
| title | Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. |
| title_full | Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. |
| title_fullStr | Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. |
| title_full_unstemmed | Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. |
| title_short | Morning and evening-type differences in slow waves during NREM sleep reveal both trait and state-dependent phenotypes. |
| title_sort | morning and evening type differences in slow waves during nrem sleep reveal both trait and state dependent phenotypes |
| url | http://europepmc.org/articles/PMC3150370?pdf=render |
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