Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice
The suprachiasmatic nucleus (SCN), which serves as the central pacemaker in mammals, regulates the 24-h rhythm in behavioral activity. However, it is currently unclear whether and how bouts of activity and rest are regulated within the 24-h cycle (i.e., over ultradian time scales). Therefore, we use...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2020-03-01
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| Series: | Frontiers in Physiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fphys.2020.00268/full |
| _version_ | 1818924078580367360 |
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| author | Bharath Ananthasubramaniam Johanna H. Meijer |
| author_facet | Bharath Ananthasubramaniam Johanna H. Meijer |
| author_sort | Bharath Ananthasubramaniam |
| collection | DOAJ |
| description | The suprachiasmatic nucleus (SCN), which serves as the central pacemaker in mammals, regulates the 24-h rhythm in behavioral activity. However, it is currently unclear whether and how bouts of activity and rest are regulated within the 24-h cycle (i.e., over ultradian time scales). Therefore, we used passive infrared sensors to measure temporal behavior in mice housed under either a light–dark (LD) cycle or continuous darkness (DD). We found that a probabilistic Markov model captures the ultradian changes in the behavioral state over a 24-h cycle. In this model, the animal’s behavioral state in the next time interval is determined solely by the animal’s current behavioral state and by the “toss” of a proverbial “biased coin.” We found that the bias of this “coin” is regulated by light input and by the phase of the clock. Moreover, the bias of this “coin” for an animal is related to the average length of rest and activity bouts in that animal. In LD conditions, the average length of rest bouts was greater during the day compared to during the night, whereas the average length of activity bouts was greater during the night compared to during the day. Importantly, we also found that day-night changes in the rest bout lengths were significantly greater than day-night changes in the activity bout lengths. Finally, in DD conditions, the activity and rest bouts also differed between subjective night and subjective day, albeit to a lesser extent compared to LD conditions. The ultradian regulation represented by the model does not result in ultradian rhythms, although some weak ultradian rhythms are present in the data. The persistent differences in bout length over the circadian cycle following loss of the external LD cycle indicate that the central pacemaker plays a role in regulating rest and activity bouts on an ultradian time scale. |
| first_indexed | 2024-12-20T02:19:37Z |
| format | Article |
| id | doaj.art-488e72e67d9a40cbb97aad3dd1a84fe7 |
| institution | Directory Open Access Journal |
| issn | 1664-042X |
| language | English |
| last_indexed | 2024-12-20T02:19:37Z |
| publishDate | 2020-03-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Physiology |
| spelling | doaj.art-488e72e67d9a40cbb97aad3dd1a84fe72022-12-21T19:56:50ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2020-03-011110.3389/fphys.2020.00268511030Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in MiceBharath Ananthasubramaniam0Johanna H. Meijer1Institute for Theoretical Biology, Charité – Universitätsmedizin Berlin, Berlin, GermanyLeiden University Medical Center, Leiden University, Leiden, NetherlandsThe suprachiasmatic nucleus (SCN), which serves as the central pacemaker in mammals, regulates the 24-h rhythm in behavioral activity. However, it is currently unclear whether and how bouts of activity and rest are regulated within the 24-h cycle (i.e., over ultradian time scales). Therefore, we used passive infrared sensors to measure temporal behavior in mice housed under either a light–dark (LD) cycle or continuous darkness (DD). We found that a probabilistic Markov model captures the ultradian changes in the behavioral state over a 24-h cycle. In this model, the animal’s behavioral state in the next time interval is determined solely by the animal’s current behavioral state and by the “toss” of a proverbial “biased coin.” We found that the bias of this “coin” is regulated by light input and by the phase of the clock. Moreover, the bias of this “coin” for an animal is related to the average length of rest and activity bouts in that animal. In LD conditions, the average length of rest bouts was greater during the day compared to during the night, whereas the average length of activity bouts was greater during the night compared to during the day. Importantly, we also found that day-night changes in the rest bout lengths were significantly greater than day-night changes in the activity bout lengths. Finally, in DD conditions, the activity and rest bouts also differed between subjective night and subjective day, albeit to a lesser extent compared to LD conditions. The ultradian regulation represented by the model does not result in ultradian rhythms, although some weak ultradian rhythms are present in the data. The persistent differences in bout length over the circadian cycle following loss of the external LD cycle indicate that the central pacemaker plays a role in regulating rest and activity bouts on an ultradian time scale.https://www.frontiersin.org/article/10.3389/fphys.2020.00268/fullspontaneous behaviorprobabilistic modellight cyclescircadian clockactivity duration |
| spellingShingle | Bharath Ananthasubramaniam Johanna H. Meijer Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice Frontiers in Physiology spontaneous behavior probabilistic model light cycles circadian clock activity duration |
| title | Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice |
| title_full | Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice |
| title_fullStr | Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice |
| title_full_unstemmed | Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice |
| title_short | Regulation of Rest, Rather Than Activity, Underlies Day-Night Activity Differences in Mice |
| title_sort | regulation of rest rather than activity underlies day night activity differences in mice |
| topic | spontaneous behavior probabilistic model light cycles circadian clock activity duration |
| url | https://www.frontiersin.org/article/10.3389/fphys.2020.00268/full |
| work_keys_str_mv | AT bharathananthasubramaniam regulationofrestratherthanactivityunderliesdaynightactivitydifferencesinmice AT johannahmeijer regulationofrestratherthanactivityunderliesdaynightactivitydifferencesinmice |