Circadian and behavioural responses to shift work-like schedules of light/dark in the mouse

McGowan, Niall M.; Coogan, Andrew N.

doi:10.1186/2049-9256-1-7

Cited by 33 publications

(28 citation statements)

References 43 publications

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“…We next sought to examine the effects of miR-132 dysregulation on time-of-day dependent measures of learning and memory. To this end, we utilized the novel object location (NOL) task-a hippocampal-dependent memory test (Barker and Warburton 2011;Chao et al 2016) with an efficiency that has previously been shown to be influenced by circadian time (McGowan and Coogan 2013;Takahashi et al 2013. The NOL task examines the ability of a mouse to remember the location of an object after moving one of the two objects in the arena.…”

Section: Mir-132 Knockout and Mir-132 Transgenic Micementioning

confidence: 99%

miR-132 couples the circadian clock to daily rhythms of neuronal plasticity and cognition

et al. 2018

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The microRNA miR-132 serves as a key regulator of a wide range of plasticity-associated processes in the central nervous system. Interestingly, miR-132 expression has also been shown to be under the control of the circadian timing system. This finding, coupled with work showing that miR-132 is expressed in the hippocampus, where it influences neuronal morphology and memory, led us to test the idea that daily rhythms in miR-132 within the forebrain modulate cognition as a function of circadian time. Here, we show that hippocampal miR-132 expression is gated by the time-of-day, with peak levels occurring during the circadian night. Further, in miR-132 knockout mice and in transgenic mice, where miR-132 is constitutively expressed under the control of the tetracycline regulator system, we found that time-of-day dependent memory recall (as assessed via novel object location and contextual fear conditioning paradigms) was suppressed. Given that miRNAs exert their functional effects via the suppression of target gene expression, we examined the effects that transgenic miR-132 manipulations have on MeCP2 and Sirt1-two miR-132 targets that are associated with neuronal plasticity and cognition. In mice where miR-132 was either knocked out, or transgenically expressed, rhythmic expression of MeCP2 and Sirt1 was suppressed. Taken together, these results raise the prospect that miR-132 serves as a key route through which the circadian timing system imparts a daily rhythm on cognitive capacity.

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Section: Mir-132 Knockout and Mir-132 Transgenic Micementioning

confidence: 99%

miR-132 couples the circadian clock to daily rhythms of neuronal plasticity and cognition

et al. 2018

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“…Rodent models of human shiftwork typically assess consequences of circadian disruption similar to that observed in human shiftwork, applying a variety of approaches including forced work during the normal rest phase (e.g., [31]), chronic jetlag (e.g., [32]), and non-entraining T-cycles (e.g., [33]). Few studies compare alternate schedules to minimize circadian disruption [34], and we are aware of no study testing different strategies to achieve a common simulated work schedule in animal models. For Study 2/DuPont and 3/Continental, we therefore developed a strategy where we aimed to evaluate and compare light-dark scheduling practices designed to avoid misalignment.…”

Section: Building Rodent Shiftwork Modelsmentioning

confidence: 99%

Enhanced Circadian Entrainment in Mice and Its Utility under Human Shiftwork Schedules

et al. 2019

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The circadian system is generally considered to be incapable of adjusting to rapid changes in sleep/work demands. In shiftworkers this leads to chronic circadian disruption and sleep loss, which together predict underperformance at work and negative health consequences. Two distinct experimental protocols have been proposed to increase circadian flexibility in rodents using dim light at night: rhythm bifurcation and T-cycle (i.e., day length) entrainment. Successful translation of such protocols to human shiftworkers could facilitate alignment of internal time with external demands. To assess entrainment flexibility following bifurcation and exposure to T-cycles, mice in Study 1 were repeatedly phase-shifted. Mice from experimental conditions rapidly phase-shifted their activity, while control mice showed expected transient misalignment. In Study 2 and 3, mice followed a several weeks-long intervention designed to model a modified DuPont or Continental shiftwork schedule, respectively. For both schedules, bifurcation and nocturnal dim lighting reduced circadian misalignment. Together, these studies demonstrate proof of concept that mammalian circadian systems can be rendered sufficiently flexible to adapt to multiple, rapidly changing shiftwork schedules. Flexible adaptation to exotic light-dark cycles likely relies on entrainment mechanisms that are distinct from traditional entrainment.

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“…56 Interestingly some animal sleep restriction or shift work studies yield contradictory results and increased weight gain was not always observed in the challenged animals. 57,58 An important factor appears to be whether the sleep/shift paradigm also triggers mistimed food intake. 56,59 Food is a strong timing signal for peripheral tissue clocks.…”

Section: Peripher Al and Centr Al Interpl Ay In Homeos Tati C And Cmentioning

confidence: 99%

Interplay of central and peripheral circadian clocks in energy metabolism regulation

Kolbe

Brehm

Oster

2018

J Neuroendocrinology

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Metabolic health founds on a homeostatic balance that has to integrate the daily changes of rest/activity and feeding/fasting cycles. A network of endogenous 24‐hour circadian clocks helps to anticipate daily recurring events and adjust physiology and behavioural functions accordingly. Circadian clocks are self‐sustained cellular oscillators based on a set of clock genes/proteins organised in interlocked transcriptional‐translational feedback loops. The body's clocks need to be regularly reset and synchronised with each other to achieve coherent rhythmic output signals. This synchronisation is achieved by interplay of a master clock, which resides in the suprachiasmatic nucleus, and peripheral tissue clocks. This clock network is reset by time signals such as the light/dark cycle, food intake and activity. The balanced interplay of clocks is easily disturbed in modern society by shiftwork or high‐energy diets, which may further promote the development of metabolic disorders. In this review, we summarise the current model of central‐peripheral clock interaction in metabolic health. Different established mouse models for central or peripheral clock disruption and their metabolic phenotypes are compared and the possible relevance of clock network interaction for the development of therapeutic approaches in humans is discussed.

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Circadian and behavioural responses to shift work-like schedules of light/dark in the mouse

Cited by 33 publications

References 43 publications

miR-132 couples the circadian clock to daily rhythms of neuronal plasticity and cognition

miR-132 couples the circadian clock to daily rhythms of neuronal plasticity and cognition

Enhanced Circadian Entrainment in Mice and Its Utility under Human Shiftwork Schedules

Interplay of central and peripheral circadian clocks in energy metabolism regulation

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