Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice
Regulatory systems required to maintain behavioral arousal remain incompletely understood. We describe a previously unappreciated role that toll-like receptor 2 (Tlr2, a membrane bound pattern recognition receptor that recognizes specific bacterial, viral, and fungal peptides), contributes toward re...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-07-01
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| Series: | Frontiers in Aging Neuroscience |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/article/10.3389/fnagi.2017.00219/full |
| _version_ | 1811319114506960896 |
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| author | Nicholas W. DeKorver Tammy R. Chaudoin Stephen J. Bonasera |
| author_facet | Nicholas W. DeKorver Tammy R. Chaudoin Stephen J. Bonasera |
| author_sort | Nicholas W. DeKorver |
| collection | DOAJ |
| description | Regulatory systems required to maintain behavioral arousal remain incompletely understood. We describe a previously unappreciated role that toll-like receptor 2 (Tlr2, a membrane bound pattern recognition receptor that recognizes specific bacterial, viral, and fungal peptides), contributes toward regulation of behavioral arousal. In 4–4.5 month old mice with constitutive loss of Tlr2 function (Tlr2−/− mice), we note a marked consolidation in the circadian pattern of both active and inactive states. Specifically, Tlr2−/− mice demonstrated significantly fewer but longer duration active states during the circadian dark cycle, and significantly fewer but longer duration inactive states during the circadian light cycle. Tlr2−/− mice also consumed less food and water, and moved less during the circadian light cycle. Analysis of circadian rhythms further suggested that Tlr2−/− mice demonstrated less day-to-day variability in feeding, drinking, and movement behaviors. Reevaluation of this same mouse cohort at age 8–8.5 months revealed a clear blunting of these differences. However, Tlr2−/− mice were still noted to have fewer short-duration active states during the circadian dark cycle, and continued to demonstrate significantly less day-to-day variability in feeding, drinking, and movement behaviors. These results suggest that Tlr2 function may have a role in promoting transitions between active and inactive states. Prior studies have demonstrated that Tlr2 regulates sickness behaviors including hypophagia, hyperthermia, and decreased activity. Our work suggests that Tlr2 function also evokes behavioral fragmentation, another aspect of sickness behavior and a clinically significant problem of older adults. |
| first_indexed | 2024-04-13T12:37:18Z |
| format | Article |
| id | doaj.art-9c62a5b9fb354fafa2651ee5db8d9aac |
| institution | Directory Open Access Journal |
| issn | 1663-4365 |
| language | English |
| last_indexed | 2024-04-13T12:37:18Z |
| publishDate | 2017-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Aging Neuroscience |
| spelling | doaj.art-9c62a5b9fb354fafa2651ee5db8d9aac2022-12-22T02:46:37ZengFrontiers Media S.A.Frontiers in Aging Neuroscience1663-43652017-07-01910.3389/fnagi.2017.00219276716Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 MiceNicholas W. DeKorverTammy R. ChaudoinStephen J. BonaseraRegulatory systems required to maintain behavioral arousal remain incompletely understood. We describe a previously unappreciated role that toll-like receptor 2 (Tlr2, a membrane bound pattern recognition receptor that recognizes specific bacterial, viral, and fungal peptides), contributes toward regulation of behavioral arousal. In 4–4.5 month old mice with constitutive loss of Tlr2 function (Tlr2−/− mice), we note a marked consolidation in the circadian pattern of both active and inactive states. Specifically, Tlr2−/− mice demonstrated significantly fewer but longer duration active states during the circadian dark cycle, and significantly fewer but longer duration inactive states during the circadian light cycle. Tlr2−/− mice also consumed less food and water, and moved less during the circadian light cycle. Analysis of circadian rhythms further suggested that Tlr2−/− mice demonstrated less day-to-day variability in feeding, drinking, and movement behaviors. Reevaluation of this same mouse cohort at age 8–8.5 months revealed a clear blunting of these differences. However, Tlr2−/− mice were still noted to have fewer short-duration active states during the circadian dark cycle, and continued to demonstrate significantly less day-to-day variability in feeding, drinking, and movement behaviors. These results suggest that Tlr2 function may have a role in promoting transitions between active and inactive states. Prior studies have demonstrated that Tlr2 regulates sickness behaviors including hypophagia, hyperthermia, and decreased activity. Our work suggests that Tlr2 function also evokes behavioral fragmentation, another aspect of sickness behavior and a clinically significant problem of older adults.http://journal.frontiersin.org/article/10.3389/fnagi.2017.00219/fullactive/inactive state consolidationsleep fragmentationTlr2 knockout mousehome cage behaviorcircadian behaviormovement |
| spellingShingle | Nicholas W. DeKorver Tammy R. Chaudoin Stephen J. Bonasera Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice Frontiers in Aging Neuroscience active/inactive state consolidation sleep fragmentation Tlr2 knockout mouse home cage behavior circadian behavior movement |
| title | Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice |
| title_full | Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice |
| title_fullStr | Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice |
| title_full_unstemmed | Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice |
| title_short | Toll-Like Receptor 2 Is a Regulator of Circadian Active and Inactive State Consolidation in C57BL/6 Mice |
| title_sort | toll like receptor 2 is a regulator of circadian active and inactive state consolidation in c57bl 6 mice |
| topic | active/inactive state consolidation sleep fragmentation Tlr2 knockout mouse home cage behavior circadian behavior movement |
| url | http://journal.frontiersin.org/article/10.3389/fnagi.2017.00219/full |
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