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Benoit JB, Ajayi OM, Webster A, Grieshop K, Lewis D, Talbott H, Bose J, Polak M. Shifted levels of sleep and activity under darkness as mechanisms underlying ectoparasite resistance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.30.564749. [PMID: 37961082 PMCID: PMC10634994 DOI: 10.1101/2023.10.30.564749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Parasites harm host fitness and are pervasive agents of natural selection to evolve host defense strategies Host defensive traits in natural populations typically show genetic variation, which may be maintained when parasite resistance imposes fitness costs on the host in the absence of parasites. Previously we demonstrated significant evolutionary responses to artificial selection for increasing behavioral immunity to Gamasodes queenslandicus mites in replicate lines of Drosophila melanogaster. Here, we report transcriptional shifts in metabolic processes between selected and control fly lines based on RNA-seq analyses. We also show decreased starvation resistance and increased use of nutrient reserves in flies from mite-resistant lines. Additionally, mite-resistant lines exhibited increased behavioral activity, such as, reduced sleep and elevated oxygen consumption under conditions of darkness. The link between resistance and sleep was confirmed in an independent panel of D. melanogaster genetic lines exhibiting variable sleep durations, showing a positive correlation between mite resistance and reduced sleep. Experimentally restraining the activity of artificially selected mite-resistant flies during exposure to parasites under dark conditions reduced their resistance advantage relative to control flies. The results suggest that ectoparasite resistance in this system involves increased dark-condition activity and metabolic gene expression at the expense of nutrient reserves and starvation resistance.
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2
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Mortlock E, Silovský V, Güldenpfennig J, Faltusová M, Olejarz A, Börger L, Ježek M, Jennings DJ, Capellini I. Sleep in the wild: the importance of individual effects and environmental conditions on sleep behaviour in wild boar. Proc Biol Sci 2024; 291:20232115. [PMID: 38808449 DOI: 10.1098/rspb.2023.2115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 04/19/2024] [Indexed: 05/30/2024] Open
Abstract
Sleep serves vital physiological functions, yet how sleep in wild animals is influenced by environmental conditions is poorly understood. Here we use high-resolution biologgers to investigate sleep in wild animals over ecologically relevant time scales and quantify variability between individuals under changing conditions. We developed a robust classification for accelerometer data and measured multiple dimensions of sleep in the wild boar (Sus scrofa) over an annual cycle. In support of the hypothesis that environmental conditions determine thermoregulatory challenges, which regulate sleep, we show that sleep quantity, efficiency and quality are reduced on warmer days, sleep is less fragmented in longer and more humid days, while greater snow cover and rainfall promote sleep quality. Importantly, this longest and most detailed analysis of sleep in wild animals to date reveals large inter- and intra-individual variation. Specifically, short-sleepers sleep up to 46% less than long-sleepers but do not compensate for their short sleep through greater plasticity or quality, suggesting they may pay higher costs of sleep deprivation. Given the major role of sleep in health, our results suggest that global warming and the associated increase in extreme climatic events are likely to negatively impact sleep, and consequently health, in wildlife, particularly in nocturnal animals.
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Affiliation(s)
- Euan Mortlock
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Václav Silovský
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol 165 00, Czech Republic
| | - Justine Güldenpfennig
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol 165 00, Czech Republic
| | - Monika Faltusová
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol 165 00, Czech Republic
| | - Astrid Olejarz
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol 165 00, Czech Republic
| | - Luca Börger
- Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, UK
| | - Miloš Ježek
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol 165 00, Czech Republic
| | - Dómhnall J Jennings
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Isabella Capellini
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
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Putyora E, Brocklehurst S, Sandilands V. The Effects of Commercially-Relevant Disturbances on Sleep Behaviour in Laying Hens. Animals (Basel) 2023; 13:3105. [PMID: 37835711 PMCID: PMC10571886 DOI: 10.3390/ani13193105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/11/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
Ensuring the welfare of commercially kept animals is a legal and ethical responsibility. Sleep behaviour can be sensitive to environmental perturbations and may be useful in assessing welfare state. The objective of this study was to use behavioural and electrophysiological (EEG) measures to observe the effects of 24 h stressors followed by periods of no stressors on laying hen sleep behaviour, and to investigate the use of sleep behaviour as a means of welfare assessment in commercial poultry. Ten laying hens surgically implanted with EEG devices to record their brain activity over four batches were used. Hens were subjected to undisturbed, disturbed and recovery periods for 24 h. Disturbed periods consisted of either feed deprivation, increased ambient temperature (28 °C) or simulated footpad pain via injection of Freund's adjuvant into the footpad. Sleep state was scored using behaviour data from infrared cameras and EEG data. Over all periods, hens engaged in both SWS (average 60%) and REM sleep (average 12%) during the lights-off period. Feed deprivation and footpad pain had little to no effect on sleep states, while increased ambient temperature significantly reduced REM sleep (to near elimination, p < 0.001) and SWS (p = 0.017). During the lights-on period, footpad pain increased the proportion of time spent resting (p = 0.008) and in SWS (p < 0.001), with feed deprivation or increased ambient temperature (p > 0.05) having no effect. Increasing ambient temperatures are likely to affect sleep and welfare in commercially-kept laying hens in the face of global climate change.
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Affiliation(s)
- Endre Putyora
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
- Department of Agriculture, Horticulture and Engineering Sciences, Scotland’s Rural College (SRUC), Edinburgh EH25 9RG, UK;
| | | | - Victoria Sandilands
- Department of Agriculture, Horticulture and Engineering Sciences, Scotland’s Rural College (SRUC), Edinburgh EH25 9RG, UK;
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Putyora E, Brocklehurst S, Tuyttens F, Sandilands V. The Effects of Mild Disturbances on Sleep Behaviour in Laying Hens. Animals (Basel) 2023; 13:ani13071251. [PMID: 37048507 PMCID: PMC10093027 DOI: 10.3390/ani13071251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 03/26/2023] [Accepted: 03/29/2023] [Indexed: 04/14/2023] Open
Abstract
The positive welfare of commercial animals presents many benefits, making the accurate assessment of welfare important. Assessments frequently use behaviour to determine welfare state; however, nighttime behaviours are often ignored. Sleep behaviour may offer new insights into welfare assessments. This study aimed to establish a baseline for sleep behaviour in laying hens and to then apply mild short-term disturbances and observe the subsequent effects. Twelve laying hens were divided into four batches and were surgically implanted with electroencephalogram (EEG) devices to record their brain activity. The batches were subjected to undisturbed, disturbed and recovery types of nights. Disturbed nights consisted of systematic sequences of disturbance application (wind, 90 dB noise or 20 lux light) applied one at a time for 5 min every 30 min from 21:00 to 03:00 (lights off period: 19:00-05:00). Sleep state was scored using EEG data and behaviour data from infrared cameras. Over all the types of night hens engaged in both SWS (58%) and REM sleep (18%) during lights off. When applied, the disturbances were effective at altering the amounts of wakefulness and SWS (Time × Type of Night, p < 0.001, p = 0.017, respectively), whereas REM sleep was unaltered (p = 0.540). There was no evidence of carry-over effects over the following day or night. Laying hens may be resilient to short-term sleep disruption by compensating for this in the same night, suggesting that these disturbances do not impact their long-term welfare (i.e., over days). Sleep behaviour potentially offers a unique means of assessing an aspect of animal welfare that, to date, has been poorly studied.
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Affiliation(s)
- Endre Putyora
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
- Department of Agriculture, Horticulture and Engineering Sciences, Scotland's Rural College (SRUC), Edinburgh EH25 9RG, UK
| | | | - Frank Tuyttens
- Department of Veterinary and Biosciences, Faculty of Veterinary Medicine, Ghent University, 9820 Merelbeke, Belgium
- Animal Sciences Unit, Flanders Research Institute for Agriculture, Fisheries and Food (ILVO), 9090 Melle, Belgium
| | - Victoria Sandilands
- Department of Agriculture, Horticulture and Engineering Sciences, Scotland's Rural College (SRUC), Edinburgh EH25 9RG, UK
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5
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Duhart JM, Inami S, Koh K. Many faces of sleep regulation: beyond the time of day and prior wake time. FEBS J 2023; 290:931-950. [PMID: 34908236 PMCID: PMC9198110 DOI: 10.1111/febs.16320] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 12/07/2021] [Accepted: 12/14/2021] [Indexed: 12/19/2022]
Abstract
The two-process model of sleep regulation posits two main processes regulating sleep: the circadian process controlled by the circadian clock and the homeostatic process that depends on the history of sleep and wakefulness. The model has provided a dominant conceptual framework for sleep research since its publication ~ 40 years ago. The time of day and prior wake time are the primary factors affecting the circadian and homeostatic processes, respectively. However, it is critical to consider other factors influencing sleep. Since sleep is incompatible with other behaviors, it is affected by the need for essential behaviors such as eating, foraging, mating, caring for offspring, and avoiding predators. Sleep is also affected by sensory inputs, sickness, increased need for memory consolidation after learning, and other factors. Here, we review multiple factors influencing sleep and discuss recent insights into the mechanisms balancing competing needs.
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Affiliation(s)
- José Manuel Duhart
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia PA
- These authors contributed equally
- Present address: Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina
| | - Sho Inami
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia PA
- These authors contributed equally
| | - Kyunghee Koh
- Department of Neuroscience, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia PA
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6
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Rattenborg NC, Ungurean G. The evolution and diversification of sleep. Trends Ecol Evol 2023; 38:156-170. [PMID: 36411158 DOI: 10.1016/j.tree.2022.10.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 10/17/2022] [Accepted: 10/24/2022] [Indexed: 11/19/2022]
Abstract
The evolutionary origins of sleep and its sub-states, rapid eye movement (REM) and non-REM (NREM) sleep, found in mammals and birds, remain a mystery. Although the discovery of a single type of sleep in jellyfish suggests that sleep evolved much earlier than previously thought, it is unclear when and why sleep diversified into multiple types of sleep. Intriguingly, multiple types of sleep have recently been found in animals ranging from non-avian reptiles to arthropods to cephalopods. Although there are similarities between these states and those found in mammals and birds, notable differences also exist. The diversity in the way sleep is expressed confounds attempts to trace the evolution of sleep states, but also serves as a rich resource for exploring the functions of sleep.
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Affiliation(s)
- Niels C Rattenborg
- Max Planck Institute for Biological Intelligence (in foundation), Seewiesen, Germany.
| | - Gianina Ungurean
- Max Planck Institute for Biological Intelligence (in foundation), Seewiesen, Germany
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7
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Woodward SH. Autonomic regulation during sleep in PTSD. Neurobiol Stress 2022; 21:100483. [DOI: 10.1016/j.ynstr.2022.100483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 08/01/2022] [Accepted: 08/25/2022] [Indexed: 10/31/2022] Open
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Zaid E, Vyssotski AL, Lesku JA. Sleep architecture and regulation of male dusky antechinus, an Australian marsupial. Sleep 2022; 45:6585950. [PMID: 35567787 PMCID: PMC9366648 DOI: 10.1093/sleep/zsac114] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 05/05/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
Study Objectives
In this study, we (1) describe sleep behavior and architecture, and (2) explore how sleep is regulated in dusky antechinus (Antechinus swainsonii), a small insectivorous marsupial. Our aim is to provide the first investigation into sleep homeostasis in a marsupial.
Methods
Wild-caught male dusky antechinus (n = 4) were individually housed in large indoor cages under a natural photoperiod of 10.5 h light/13.5 h dark. Continuous recordings of EEG, EMG, and tri-axial accelerometry were performed under baseline conditions and following 4-h of extended wakefulness.
Results
Antechinus engage in SWS and REM sleep. Some aspects of these states are mammal-like, including a high amount (23%) of REM sleep, but other features are reminiscent of birds, notably, hundreds of short sleep episodes (SWS mean: 34 s; REM sleep: 10 s). Antechinus are cathemeral and sleep equally during the night and day. Immediately after the sleep deprivation ended, the animals engaged in more SWS, longer SWS episodes, and greater SWS SWA. The animals did not recover lost REM sleep.
Conclusions
Sleep architecture in dusky antechinus was broadly similar to that observed in eutherian and marsupial mammals, but with interesting peculiarities. We also provided the first evidence of SWS homeostasis in a marsupial mammal.
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Affiliation(s)
- Erika Zaid
- School of Agriculture, Biomedicine and Environment, La Trobe University , Melbourne , Australia
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich/ETH Zurich , Zurich , Switzerland
| | - John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University , Melbourne , Australia
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9
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Smeltzer EA, Stead SM, Li MF, Samson D, Kumpan LT, Teichroeb JA. Social sleepers: The effects of social status on sleep in terrestrial mammals. Horm Behav 2022; 143:105181. [PMID: 35594742 DOI: 10.1016/j.yhbeh.2022.105181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 04/12/2022] [Accepted: 04/22/2022] [Indexed: 11/18/2022]
Abstract
Social status among group-living mammals can impact access to resources, such as water, food, social support, and mating opportunities, and this differential access to resources can have fitness consequences. Here, we propose that an animal's social status impacts their access to sleep opportunities, as social status may predict when an animal sleeps, where they sleep, who they sleep with, and how well they sleep. Our review of terrestrial mammals examines how sleep architecture and intensity may be impacted by (1) sleeping conditions and (2) the social experience during wakefulness. Sleeping positions vary in thermoregulatory properties, protection from predators, and exposure to parasites. Thus, if dominant individuals have priority of access to sleeping positions, they may benefit from higher quality sleeping conditions and, in turn, better sleep. With respect to waking experiences, we discuss the impacts of stress on sleep, as it has been established that specific social statuses can be characterized by stress-related physiological profiles. While much research has focused on how dominance hierarchies impact access to resources like food and mating opportunities, differential access to sleep opportunities among mammals has been largely ignored despite its potential fitness consequences.
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Affiliation(s)
- E A Smeltzer
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario M1C 1A4, Canada
| | - S M Stead
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario M1C 1A4, Canada.
| | - M F Li
- Department of Anthropology, University of Toronto, 19 Russell St., Toronto, Ontario M5S 2S2, Canada
| | - D Samson
- Department of Anthropology, University of Toronto Mississauga, 3359 Mississauga Rd., Mississauga, Ontario L5L 1C6, Canada
| | - L T Kumpan
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario M1C 1A4, Canada
| | - J A Teichroeb
- Department of Anthropology, University of Toronto Scarborough, 1265 Military Trail, Scarborough, Ontario M1C 1A4, Canada
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10
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Lemos de Figueiredo R, Hartley M, Fletcher AW. Assessing the behaviour, welfare and husbandry of mouse deer (Tragulus spp.) in European zoos. Appl Anim Behav Sci 2021. [DOI: 10.1016/j.applanim.2021.105283] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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11
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Comparative Perspectives that Challenge Brain Warming as the Primary Function of REM Sleep. iScience 2020; 23:101696. [PMID: 33196022 PMCID: PMC7644584 DOI: 10.1016/j.isci.2020.101696] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 09/17/2020] [Accepted: 10/14/2020] [Indexed: 01/04/2023] Open
Abstract
Rapid eye movement (REM) sleep is a paradoxical state of wake-like brain activity occurring after non-REM (NREM) sleep in mammals and birds. In mammals, brain cooling during NREM sleep is followed by warming during REM sleep, potentially preparing the brain to perform adaptively upon awakening. If brain warming is the primary function of REM sleep, then it should occur in other animals with similar states. We measured cortical temperature in pigeons and bearded dragons, lizards that exhibit NREM-like sleep and REM-like sleep with brain activity resembling wakefulness. In pigeons, cortical temperature decreased during NREM sleep and increased during REM sleep. However, brain temperature did not increase when dragons switched from NREM-like to REM-like sleep. Our findings indicate that brain warming is not a universal outcome of sleep states characterized by wake-like activity, challenging the hypothesis that their primary function is to warm the brain in preparation for wakefulness. In many mammals, the brain cools during non-REM sleep and warms during REM sleep Pigeons exhibit similar changes in cortical temperature during non-REM and REM sleep Brain temperature does not increase during REM-like sleep in bearded dragon lizards Brain warming is not a universal outcome of sleep states with wake-like brain activity
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12
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Tam SKE, Bannerman DM, Peirson SN. Mechanisms mediating the effects of light on sleep and alertness: current challenges. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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14
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Burger AL, Fennessy J, Fennessy S, Dierkes PW. Nightly selection of resting sites and group behavior reveal antipredator strategies in giraffe. Ecol Evol 2020; 10:2917-2927. [PMID: 32211165 PMCID: PMC7083675 DOI: 10.1002/ece3.6106] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 12/28/2022] Open
Abstract
This study presents the first findings on nocturnal behavior patterns of wild Angolan giraffe. We characterized their nocturnal behavior and analyzed the influence of ecological factors such as group size, season, and habitat use. Giraffe were observed using night vision systems and thermal imaging cameras on Okapuka Ranch, Namibia. A total of 77 giraffe were observed during 24 nights over two distinct periods-July-August 2016 (dry season) and February-March 2017 (wet season). Photoperiod had a marked influence on their activity and moving behavior. At dusk, giraffe reduced the time spent moving and increasingly lay down and slept at the onset of darkness. Body postures that likely correspond to rapid eye movement (REM) sleep posture (RSP) were observed 15.8 ± 18.3 min after giraffe sat down. Season had a significant effect with longer RSP phases during the dry season (dry: 155.2 ± 191.1 s, n = 79; wet: 85.8 ± 94.9 s, n = 73). Further analyses of the influence of social behavior patterns did not show an effect of group size on RSP lengths. When a group of giraffe spent time at a specific resting site, several individuals were alert (vigilant) while other group members sat down or took up RSP. Simultaneous RSP events within a group were rarely observed. Resting sites were characterized by single trees or sparse bushes on open areas allowing for good visibility in a relatively sheltered location.
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Affiliation(s)
- Anna Lena Burger
- Bioscience Education and Zoo BiologyGoethe University FrankfurtFrankfurt am MainGermany
| | - Julian Fennessy
- Giraffe Conservation FoundationWindhoekNamibia
- School of Biological, Earth and Environmental SciencesUniversity of New South WalesSydneyNSWAustralia
| | | | - Paul W. Dierkes
- Bioscience Education and Zoo BiologyGoethe University FrankfurtFrankfurt am MainGermany
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15
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Abstract
For many decades, sleep researchers have sought to determine which species 'have' rapid eye movement (REM) sleep. In doing so, they relied predominantly on a template derived from the expression of REM sleep in the adults of a small number of mammalian species. Here, we argue for a different approach that focuses less on a binary decision about haves and have nots, and more on the diverse expression of REM sleep components over development and across species. By focusing on the components of REM sleep and discouraging continued reliance on a restricted template, we aim to promote a richer and more biologically grounded developmental-comparative approach that spans behavioral, physiological, neural, and ecological domains.
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Affiliation(s)
- Mark S Blumberg
- Department of Psychological and Brain Sciences, Iowa Neuroscience Institute, University of Iowa, Iowa City, IA 52242, USA.
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
| | - Paul-Antoine Libourel
- Neurosciences Research Center of Lyon, CNRS UMR5292, INSERM U1028, University Claude Bernard Lyon 1 Neurocampus, 95 Boulevard Pinel, 69675 BRON, France
| | - Markus H Schmidt
- Department of Neurology, Bern University Hospital (Inselspital), University of Bern, Freiburgstrasse 18, 3010 Bern, Switzerland; Ohio Sleep Medicine Institute, 4975 Bradenton Avenue, Dublin, OH 43017, USA
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany.
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16
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Nagari M, Gera A, Jonsson S, Bloch G. Bumble Bee Workers Give Up Sleep to Care for Offspring that Are Not Their Own. Curr Biol 2019; 29:3488-3493.e4. [DOI: 10.1016/j.cub.2019.07.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 07/09/2019] [Accepted: 07/31/2019] [Indexed: 01/26/2023]
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17
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Tworkowski L, Lesku JA. Behavioural Ecology: Sleeping Safely Carries Energetic Costs. Curr Biol 2019; 29:R801-R803. [DOI: 10.1016/j.cub.2019.07.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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18
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Hutton P, Wright CD, DeNardo DF, McGraw KJ. No Effect of Human Presence at Night on Disease, Body Mass, or Metabolism in Rural and Urban House Finches (Haemorhous mexicanus). Integr Comp Biol 2019; 58:977-985. [PMID: 29986043 DOI: 10.1093/icb/icy093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Global urban development continues to accelerate and have diverse effects on wildlife. Although most studies of anthropogenic impacts on animals have focused on indirect effects (e.g., environmental modifications like habitat change or pollution), there may also be direct effects of physical human presence and actions on wildlife stress, behavior, and persistence in cities. Most studies on how humans physically interact with wildlife have focused on the active, daytime phase of diurnal animals, rarely considering effects of our night-time activities. We hypothesized that, if night-time human presence is a stressor for wildlife that are not commonly exposed to humans, night-disturbed rural animals would show stronger physiological signs of elevated stress than would urban individuals. Specifically, we experimentally investigated the effects of human presence at night (HPAN) on disease, body mass, and mass-specific metabolic rates in urban- and rural-caught house finches (Haemorhous mexicanus) in captivity. Our HPAN treatment consisted of a human entering the housing room of the birds and briefly jostling the home cages of each finch as the person walked around the room for a 3-min period on five randomly selected nights per week. Compared with a control (night-undisturbed) group, we found that HPAN greatly increased the odds finches were awake for ca. 33 min post-disturbance, but that chronic treatment did not alter body mass, parasitic infection by coccidian endoparasites, or mass-specific basal metabolic rates. Additionally, finches caught from urban and rural sites did not differ in their response to the treatment. Overall, our results are consistent with those showing that brief but regular human disturbances can have acute negative effects on wildlife, but carry few if any long-term metabolic or disease-related costs in fast-lived birds. However, these findings contrast with the broad, chronic physiological effects of other anthropogenic changes, such as artificial light at night, and highlight the differential impacts that various human activities (which differ in sensory stimulus type, perceived threat, duration and intensity, etc.) can have on wildlife health and behavior.
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Affiliation(s)
- Pierce Hutton
- School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Christian D Wright
- School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Dale F DeNardo
- School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
| | - Kevin J McGraw
- School of Life Sciences, College of Liberal Arts and Sciences, Arizona State University, Tempe, AZ 85287-4501, USA
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Faria GS, Varela SAM, Gardner A. The social evolution of sleep: sex differences, intragenomic conflicts and clinical pathologies. Proc Biol Sci 2019; 286:20182188. [PMID: 30963856 PMCID: PMC6367171 DOI: 10.1098/rspb.2018.2188] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/30/2018] [Indexed: 12/14/2022] Open
Abstract
Sleep appears to be essential for most animals, including humans. Accordingly, individuals who sacrifice sleep are expected to incur costs and so should only be evolutionarily favoured to do this when these costs are offset by other benefits. For instance, a social group might benefit from having some level of wakefulness during the sleeping period if this guards against possible threats. Alternatively, individuals might sacrifice sleep in order to gain an advantage over mate competitors. Here, we perform a theoretical analysis of the social evolutionary pressures that drive investment into sleep versus wakefulness. Specifically, we: investigate how relatedness between social partners may modulate sleeping strategies, depending upon whether sleep sacrifice is selfish or altruistic; determine the conditions under which the sexes are favoured to adopt different sleeping strategies; identify the potential for intragenomic conflict between maternal-origin versus paternal-origin genes regarding an individual's sleeping behaviour; translate this conflict into novel and readily testable predictions concerning patterns of gene expression; and explore the concomitant effects of different kinds of mutations, epimutations, and uniparental disomies in relation to sleep disorders and other clinical pathologies. Our aim is to provide a theoretical framework for future empirical data and stimulate further research on this neglected topic.
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Affiliation(s)
- Gonçalo S. Faria
- School of Biology, University of St Andrews, Dyers Brae, St Andrews KY16 9TH, UK
| | - Susana A. M. Varela
- Instituto Gulbenkian de Ciência, 6 Rua da Quinta Grande, 2780-156 Oeiras, Portugal
- cE3c – Centre for Ecology, Evolution and Environmental Changes, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Andy Gardner
- School of Biology, University of St Andrews, Dyers Brae, St Andrews KY16 9TH, UK
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Tisdale RK, Lesku JA, Beckers GJL, Vyssotski AL, Rattenborg NC. The low-down on sleeping down low: pigeons shift to lighter forms of sleep when sleeping near the ground. J Exp Biol 2018; 221:221/19/jeb182634. [DOI: 10.1242/jeb.182634] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 07/30/2018] [Indexed: 12/21/2022]
Abstract
ABSTRACT
Sleep in birds is composed of two distinct sub-states, remarkably similar to mammalian slow-wave sleep (SWS) and rapid eye movement (REM) sleep. However, it is unclear whether all aspects of mammalian sleep are present in birds. We examined whether birds suppress REM sleep in response to changes in sleeping conditions that presumably evoke an increase in perceived predation risk, as observed previously in rodents. Although pigeons sometimes sleep on the ground, they prefer to sleep on elevated perches at night, probably to avoid nocturnal mammalian ground predators. Few studies to date have investigated how roosting sites affect sleep architecture. We compared sleep in captive pigeons on days with and without access to high perches. On the first (baseline) day, low and high perches were available; on the second day, the high perches were removed; and on the third (recovery) day, the high perches were returned. The total time spent sleeping did not vary significantly between conditions; however, the time spent in REM sleep declined on the low-perch night and increased above baseline when the pigeons slept on the high perch during the recovery night. Although the amount of SWS did not vary significantly between conditions, SWS intensity was lower on the low-perch night, particularly early in the night. The similarity of these responses between birds and mammals suggests that REM sleep is influenced by at least some ecological factors in a similar manner in both groups of animals.
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Affiliation(s)
- Ryan K. Tisdale
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
| | - John A. Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
| | - Gabriel J. L. Beckers
- Cognitive Neurobiology and Helmholtz Institute, Utrecht University, Utrecht 3584 CM, The Netherlands
| | - Alexei L. Vyssotski
- Institute of Neuroinformatics, University of Zürich/ETH Zürich, Zürich 8057, Switzerland
| | - Niels C. Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen 82319, Germany
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Hargis K, Buechel HM, Popovic J, Blalock EM. Acute psychosocial stress in mid-aged male rats causes hyperthermia, cognitive decline, and increased deep sleep power, but does not alter deep sleep duration. Neurobiol Aging 2018; 70:78-85. [PMID: 30007167 PMCID: PMC6119089 DOI: 10.1016/j.neurobiolaging.2018.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 05/08/2018] [Accepted: 06/05/2018] [Indexed: 10/14/2022]
Abstract
Aging is associated with altered sleep architecture and worsened hippocampus-dependent cognition, highly prevalent clinical conditions that detract from quality of life for the elderly. Interestingly, exposure to psychosocial stress causes similar responses in young subjects, suggesting that age itself may act as a stressor. In prior work, we demonstrated that young animals show loss of deep sleep, deficits in cognition, and elevated body temperature after acute stress exposure, whereas aged animals are hyporesponsive on these measures. However, it is unclear if these age-altered stress responses occur in parallel over the course of aging. To address this, here we repeated the experiment in mid-aged animals. We hypothesized that mid-aged stress responses would be intermediate between those of young and aged subjects. Sixteen mid-aged (12 months) male F344 rats were implanted with EEG/EMG emitters to monitor sleep architecture and body temperature, and were trained on the Morris water maze for 3 days. On the fourth day, half of the subjects were restrained for 3 hours immediately before the water maze probe trial. Sleep architecture and body temperature were measured during the ensuing inactive period, and on the following day, endpoint measures were taken. Restrained mid-aged animals showed resistance to deep sleep loss, but demonstrated stress-induced water maze probe trial performance deficits as well as postrestraint hyperthermia. Taken in the context of prior work, these data suggest that age-related loss of sleep architecture stress sensitivity may precede both cognitive and body temperature-related stress insensitivity.
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Affiliation(s)
- Kendra Hargis
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Heather M Buechel
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Jelena Popovic
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Eric M Blalock
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, USA.
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Cruz-Aguilar MA, Hernández-González M, Guevara MA, Hernández-Arteaga E, Hidalgo Aguirre RM, Amezcua Gutiérrez CDC, Ramírez-Salado I. Alpha electroencephalographic activity during rapid eye movement sleep in the spider monkey (Ateles geoffroyi
): An index of arousal during sleep? JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:557-569. [DOI: 10.1002/jez.2220] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 06/21/2018] [Accepted: 07/17/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Manuel Alejandro Cruz-Aguilar
- Laboratorio de Cronobiología y Sueño; Instituto Nacional de Psiquiatría “Ramón de la Fuente Muñiz,” Dirección de Investigaciones en Neurociencias, Ciudad de México; México
- Laboratorio de Correlación Electroencefalográfica y Conducta; Instituto de Neurociencias, CUCBA, Universidad de Guadalajara; Guadalajara México
| | - Marisela Hernández-González
- Laboratorio de Neurofisiología de la Conducta Reproductiva; Instituto de Neurociencias, CUCBA, Universidad de Guadalajara; Guadalajara México
| | - Miguel Angel Guevara
- Laboratorio de Correlación Electroencefalográfica y Conducta; Instituto de Neurociencias, CUCBA, Universidad de Guadalajara; Guadalajara México
| | - Enrique Hernández-Arteaga
- Laboratorio de Neurofisiología de la Conducta Reproductiva; Instituto de Neurociencias, CUCBA, Universidad de Guadalajara; Guadalajara México
| | - Rosa María Hidalgo Aguirre
- Departamento de Ciencias de la Salud, Laboratorio de Neuropsicología, División de Neurociencias; Centro Universitario de los Valles, Universidad de Guadalajara; Ameca México
| | | | - Ignacio Ramírez-Salado
- Laboratorio de Cronobiología y Sueño; Instituto Nacional de Psiquiatría “Ramón de la Fuente Muñiz,” Dirección de Investigaciones en Neurociencias, Ciudad de México; México
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Rattenborg NC, de la Iglesia HO, Kempenaers B, Lesku JA, Meerlo P, Scriba MF. Sleep research goes wild: new methods and approaches to investigate the ecology, evolution and functions of sleep. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0251. [PMID: 28993495 DOI: 10.1098/rstb.2016.0251] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2017] [Indexed: 11/12/2022] Open
Abstract
Despite being a prominent aspect of animal life, sleep and its functions remain poorly understood. As with any biological process, the functions of sleep can only be fully understood when examined in the ecological context in which they evolved. Owing to technological constraints, until recently, sleep has primarily been examined in the artificial laboratory environment. However, new tools are enabling researchers to study sleep behaviour and neurophysiology in the wild. Here, we summarize the various methods that have enabled sleep researchers to go wild, their strengths and weaknesses, and the discoveries resulting from these first steps outside the laboratory. The initial studies to 'go wild' have revealed a wealth of interindividual variation in sleep, and shown that sleep duration is not even fixed within an individual, but instead varies in response to an assortment of ecological demands. Determining the costs and benefits of this inter- and intraindividual variation in sleep may reveal clues to the functions of sleep. Perhaps the greatest surprise from these initial studies is that the reduction in neurobehavioural performance resulting from sleep loss demonstrated in the laboratory is not an obligatory outcome of reduced sleep in the wild.This article is part of the themed issue 'Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals'.
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Affiliation(s)
- Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | | | - Bart Kempenaers
- Department of Behavioral Ecology and Evolutionary Genetics, Max Planck Institute for Ornithology, 82319 Seewiesen, Germany
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, 9700 Groningen, The Netherlands
| | - Madeleine F Scriba
- Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
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25
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Fumagalli M, Cesario A, Costa M, Harraway J, Notarbartolo di Sciara G, Slooten E. Behavioural responses of spinner dolphins to human interactions. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172044. [PMID: 29765660 PMCID: PMC5936925 DOI: 10.1098/rsos.172044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 03/20/2018] [Indexed: 05/10/2023]
Abstract
There is increasing evidence that whale and dolphin watching activities have detrimental effects on targeted cetacean populations. In Egypt, spinner dolphins regularly occur in the resting areas of Samadai, Satayah and Qubbat'Isa reefs. In-water human interactions with dolphins are regulated with a time-area closure system at Samadai, unregulated at Satayah and non-existent at Qubbat'Isa. This provided an ideal experimental setting to advance our understanding of the effects of tourism on a species highly sensitive to disturbances. Our study confirmed that the intensity and duration of interactions, and therefore, dolphin exposure to tourism, differed among the study sites. Compared with the Qubbat'Isa control site, behavioural reactions to boats and swimmers at the two tourism sites suggested that dolphin rest was disrupted, especially around the middle of the day and especially at Satayah, where dolphin tourism is unregulated. Our results indicate also that the dolphin protection measures at Samadai reduce the level of disturbance. We recommend that similar measures be implemented at other dolphin tourism locations, and that no new operations be initiated until the long-term impacts on dolphin populations are better understood. Our experience emphasizes the need to adopt precautionary approaches in research and management of whale and dolphin watching.
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Affiliation(s)
- Maddalena Fumagalli
- Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9054, New Zealand
- Tethys Research Institute, Viale G.B. Gadio 2, Milano 20121, Italy
- Author for correspondence: Maddalena Fumagalli e-mail:
| | - Amina Cesario
- Tethys Research Institute, Viale G.B. Gadio 2, Milano 20121, Italy
- The Swire Institute of Marine Science, University of Hong Kong, Pokfulam Road, Hong Kong SAR, People's Republic of China
| | - Marina Costa
- Tethys Research Institute, Viale G.B. Gadio 2, Milano 20121, Italy
- South Atlantic Environmental Research Institute (SAERI), Stanley Cottage, Falkland Islands
| | - John Harraway
- Department of Mathematics and Statistics, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand
| | | | - Elisabeth Slooten
- Department of Zoology, University of Otago, 340 Great King Street, Dunedin 9054, New Zealand
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Eban-Rothschild A, Appelbaum L, de Lecea L. Neuronal Mechanisms for Sleep/Wake Regulation and Modulatory Drive. Neuropsychopharmacology 2018; 43:937-952. [PMID: 29206811 PMCID: PMC5854814 DOI: 10.1038/npp.2017.294] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 11/17/2017] [Accepted: 11/24/2017] [Indexed: 12/17/2022]
Abstract
Humans have been fascinated by sleep for millennia. After almost a century of scientific interrogation, significant progress has been made in understanding the neuronal regulation and functions of sleep. The application of new methods in neuroscience that enable the analysis of genetically defined neuronal circuits with unprecedented specificity and precision has been paramount in this endeavor. In this review, we first discuss electrophysiological and behavioral features of sleep/wake states and the principal neuronal populations involved in their regulation. Next, we describe the main modulatory drives of sleep and wakefulness, including homeostatic, circadian, and motivational processes. Finally, we describe a revised integrative model for sleep/wake regulation.
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Affiliation(s)
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan, Israel
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, USA
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Gravett N, Bhagwandin A, Lyamin OI, Siegel JM, Manger PR. Sociality Affects REM Sleep Episode Duration Under Controlled Laboratory Conditions in the Rock Hyrax, Procavia capensis. Front Neuroanat 2017; 11:105. [PMID: 29201001 PMCID: PMC5696350 DOI: 10.3389/fnana.2017.00105] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 11/03/2017] [Indexed: 11/18/2022] Open
Abstract
The rock hyrax, Procavia capensis, is a highly social, diurnal mammal. In the current study several physiologically measurable parameters of sleep, as well as the accompanying behavior, were recorded continuously from five rock hyraxes, for 72 h under solitary (experimental animal alone in the recording chamber), and social conditions (experimental animal with 1 or 2 additional, non-implanted animals in the recording chamber). The results revealed no significant differences between solitary and social conditions for total sleep times, number of episodes, episode duration or slow wave activity (SWA) for all states examined. The only significant difference observed between social and solitary conditions was the average duration of rapid eye movement (REM) sleep episodes. REM sleep episode duration was on average 20 s and 40 s longer under social conditions daily and during the dark period, respectively. It is hypothesized that the increase in REM sleep episode duration under social conditions could possibly be attributed to improved thermoregulation strategies, however considering the limited sample size and design of the current study further investigations are needed to confirm this finding. Whether the conclusions and the observations made in this study can be generalized to all naturally socially sleeping mammals remains an open question.
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Affiliation(s)
- Nadine Gravett
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Oleg I Lyamin
- Department of Psychiatry, School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Brain Research Institute, Neurobiology Research, Sepulveda VA Medical Centre, Los Angeles, CA, United States
| | - Jerome M Siegel
- Department of Psychiatry, School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States.,Brain Research Institute, Neurobiology Research, Sepulveda VA Medical Centre, Los Angeles, CA, United States
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Eban-Rothschild A, Giardino WJ, de Lecea L. To sleep or not to sleep: neuronal and ecological insights. Curr Opin Neurobiol 2017; 44:132-138. [PMID: 28500869 DOI: 10.1016/j.conb.2017.04.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 04/07/2017] [Accepted: 04/20/2017] [Indexed: 12/13/2022]
Abstract
Daily, animals need to decide when to stop engaging in cognitive processes and behavioral responses to the environment, and go to sleep. The main processes regulating the daily organization of sleep and wakefulness are circadian rhythms and homeostatic sleep pressure. In addition, motivational processes such as food seeking and predator evasion can modulate sleep/wake behaviors. Here, we discuss the principal processes regulating the propensity to stay awake or go to sleep-focusing on neuronal and behavioral aspects. We first introduce the neuronal populations involved in sleep/wake regulation. Next, we describe the circadian and homeostatic drives for sleep. Then, we highlight studies demonstrating various effects of motivational processes on sleep/wake behaviors, and discuss possible neuronal mechanisms underlying their control.
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Affiliation(s)
- Ada Eban-Rothschild
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
| | - William J Giardino
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, 1201 Welch Road, Stanford, CA 94305, USA.
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Eban-Rothschild A, de Lecea L. Neuronal substrates for initiation, maintenance, and structural organization of sleep/wake states. F1000Res 2017; 6:212. [PMID: 28357049 PMCID: PMC5345773 DOI: 10.12688/f1000research.9677.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/20/2017] [Indexed: 11/20/2022] Open
Abstract
Animals continuously alternate between sleep and wake states throughout their life. The daily organization of sleep and wakefulness is orchestrated by circadian, homeostatic, and motivational processes. Over the last decades, much progress has been made toward determining the neuronal populations involved in sleep/wake regulation. Here, we will discuss how the application of advanced
in vivo tools for cell type–specific manipulations now permits the functional interrogation of different features of sleep/wake state regulation: initiation, maintenance, and structural organization. We will specifically focus on recent studies examining the roles of wake-promoting neuronal populations.
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Affiliation(s)
- Ada Eban-Rothschild
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA
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Kim DJ, St. Louis N, Molaro RA, Hudson GT, Chorley RC, Anderson BJ. Repeated unpredictable threats without harm impair spatial working memory in the Barnes maze. Neurobiol Learn Mem 2017; 137:92-100. [DOI: 10.1016/j.nlm.2016.11.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 11/04/2016] [Accepted: 11/19/2016] [Indexed: 10/20/2022]
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Libourel PA, Herrel A. Sleep in amphibians and reptiles: a review and a preliminary analysis of evolutionary patterns. Biol Rev Camb Philos Soc 2015; 91:833-66. [DOI: 10.1111/brv.12197] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 04/22/2015] [Accepted: 04/28/2015] [Indexed: 01/18/2023]
Affiliation(s)
- Paul-Antoine Libourel
- SLEEP - Physiopathologie des Réseaux Neuronaux du Cycle Sommeil, Centre de Recherche en Neurosciences de Lyon, Inserm U1028 - CNRS UMR5292, Faculté de Médecine Laennec; 7 rue Guillaume Paradin 69372 Lyon Cedex 08 France
| | - Anthony Herrel
- Département d'Ecologie et de Gestion de la Biodiversité; UMR 7179 C.N.R.S/M.N.H.N.; 57 rue Cuvier, Case Postale 55 75231 Paris Cedex 05 France
- Evolutionary Morphology of Vertebrates; Ghent University; K.L. Ledeganckstraat 35 B-9000 Gent Belgium
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Hirsch PE, Cayon D, Svanbäck R. Plastic responses of a sessile prey to multiple predators: a field and experimental study. PLoS One 2014; 9:e115192. [PMID: 25517986 PMCID: PMC4269437 DOI: 10.1371/journal.pone.0115192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 11/19/2014] [Indexed: 11/22/2022] Open
Abstract
Background Theory predicts that prey facing a combination of predators with different feeding modes have two options: to express a response against the feeding mode of the most dangerous predator, or to express an intermediate response. Intermediate phenotypes protect equally well against several feeding modes, rather than providing specific protection against a single predator. Anti-predator traits that protect against a common feeding mode displayed by all predators should be expressed regardless of predator combination, as there is no need for trade-offs. Principal Findings We studied phenotypic anti-predator responses of zebra mussels to predation threat from a handling-time-limited (crayfish) and a gape-size-limited (roach) predator. Both predators dislodge mussels from the substrate but diverge in their further feeding modes. Mussels increased expression of a non-specific defense trait (attachment strength) against all combinations of predators relative to a control. In response to roach alone, mussels showed a tendency to develop a weaker and more elongated shell. In response to crayfish, mussels developed a harder and rounder shell. When exposed to either a combination of predators or no predator, mussels developed an intermediate phenotype. Mussel growth rate was positively correlated with an elongated weaker shell and negatively correlated with a round strong shell, indicating a trade-off between anti-predator responses. Field observations of prey phenotypes revealed the presence of both anti-predator phenotypes and the trade-off with growth, but intra-specific population density and bottom substrate had a greater influence than predator density. Conclusions Our results show that two different predators can exert both functionally equivalent and inverse selection pressures on a single prey. Our field study suggests that abiotic factors and prey population density should be considered when attempting to explain phenotypic diversity in the wild.
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Affiliation(s)
- Philipp Emanuel Hirsch
- Department of Ecology and Evolution, Limnology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
- * E-mail:
| | - David Cayon
- Department of Ecology and Evolution, Limnology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Richard Svanbäck
- Department of Ecology and Evolution, Limnology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
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Stuber EF, Grobis MM, Abbey-Lee R, Kempenaers B, Mueller JC, Dingemanse NJ. Perceived predation risk affects sleep behaviour in free-living great tits, Parus major. Anim Behav 2014. [DOI: 10.1016/j.anbehav.2014.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Scriba MF, Rattenborg NC, Dreiss AN, Vyssotski AL, Roulin A. Sleep and vigilance linked to melanism in wild barn owls. J Evol Biol 2014; 27:2057-68. [PMID: 25056556 DOI: 10.1111/jeb.12450] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 06/02/2014] [Accepted: 06/19/2014] [Indexed: 02/03/2023]
Abstract
Understanding the function of variation in sleep requires studies in the natural ecological conditions in which sleep evolved. Sleep has an impact on individual performance and hence may integrate the costs and benefits of investing in processes that are sensitive to sleep, such as immunity or coping with stress. Because dark and pale melanic animals differentially regulate energy homeostasis, immunity and stress hormone levels, the amount and/or organization of sleep may covary with melanin-based colour. We show here that wild, cross-fostered nestling barn owls (Tyto alba) born from mothers displaying more black spots had shorter non-REM (rapid eye movement) sleep bouts, a shorter latency until the occurrence of REM sleep after a bout of wakefulness and more wakefulness bouts. In male nestlings, the same sleep traits also correlated with their own level of spotting. Because heavily spotted male nestlings and the offspring of heavily spotted biological mothers switched sleep-wakefulness states more frequently, we propose the hypothesis that they could be also behaviourally more vigilant. Accordingly, nestlings from mothers displaying many black spots looked more often towards the nest entrance where their parents bring food and towards their sibling against whom they compete. Owlets from heavily spotted mothers might invest more in vigilance, thereby possibly increasing associated costs due to sleep fragmentation. We conclude that different strategies of the regulation of brain activity have evolved and are correlated with melanin-based coloration.
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Affiliation(s)
- M F Scriba
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland; Avian Sleep Group, Max Planck Institute for Ornithology, Seewiesen, Germany
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Voirin B, Scriba MF, Martinez-Gonzalez D, Vyssotski AL, Wikelski M, Rattenborg NC. Ecology and neurophysiology of sleep in two wild sloth species. Sleep 2014; 37:753-61. [PMID: 24899764 DOI: 10.5665/sleep.3584] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Interspecific variation in sleep measured in captivity correlates with various physiological and environmental factors, including estimates of predation risk in the wild. However, it remains unclear whether prior comparative studies have been confounded by the captive recording environment. Herein we examine the effect of predation pressure on sleep in sloths living in the wild. DESIGN Comparison of two closely related sloth species, one exposed to predation and one free from predation. SETTING Panamanian mainland rainforest (predators present) and island mangrove (predators absent). PARTICIPANTS Mainland (Bradypus variegatus, five males and four females) and island (Bradypus pygmaeus, six males) sloths. INTERVENTIONS None. MEASUREMENTS AND RESULTS Electroencephalographic (EEG) and electromyographic (EMG) activity was recorded using a miniature data logger. Although both species spent between 9 and 10 h per day sleeping, the mainland sloths showed a preference for sleeping at night, whereas island sloths showed no preference for sleeping during the day or night. Standardized EEG activity during nonrapid eye movement (NREM) sleep showed lower low-frequency power, and increased spindle and higher frequency power in island sloths when compared to mainland sloths. CONCLUSIONS In sloths sleeping in the wild, predation pressure influenced the timing of sleep, but not the amount of time spent asleep. The preference for sleeping at night in mainland sloths may be a strategy to avoid detection by nocturnal cats. The pronounced differences in the NREM sleep EEG spectrum remain unexplained, but might be related to genetic or environmental factors.
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Affiliation(s)
- Bryson Voirin
- Avian Sleep Group, Max Planck Institute for Ornithology - Seewiesen, Seewiesen, Germany ; Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology - Radolfzell, Radolfzell, Germany ; Smithsonian Tropical Research Institute - Panama, Balboa, Ancón, Panama
| | - Madeleine F Scriba
- Avian Sleep Group, Max Planck Institute for Ornithology - Seewiesen, Seewiesen, Germany ; Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
| | | | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Martin Wikelski
- Department of Migration and Immuno-Ecology, Max Planck Institute for Ornithology - Radolfzell, Radolfzell, Germany ; Department of Biology, University of Konstanz, Konstanz, Germany
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology - Seewiesen, Seewiesen, Germany
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Mammalian rest/activity patterns explained by physiologically based modeling. PLoS Comput Biol 2013; 9:e1003213. [PMID: 24039566 PMCID: PMC3764015 DOI: 10.1371/journal.pcbi.1003213] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 07/23/2013] [Indexed: 12/15/2022] Open
Abstract
Circadian rhythms are fundamental to life. In mammals, these rhythms are generated by pacemaker neurons in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN is remarkably consistent in structure and function between species, yet mammalian rest/activity patterns are extremely diverse, including diurnal, nocturnal, and crepuscular behaviors. Two mechanisms have been proposed to account for this diversity: (i) modulation of SCN output by downstream nuclei, and (ii) direct effects of light on activity. These two mechanisms are difficult to disentangle experimentally and their respective roles remain unknown. To address this, we developed a computational model to simulate the two mechanisms and their influence on temporal niche. In our model, SCN output is relayed via the subparaventricular zone (SPZ) to the dorsomedial hypothalamus (DMH), and thence to ventrolateral preoptic nuclei (VLPO) and lateral hypothalamus (LHA). Using this model, we generated rich phenotypes that closely resemble experimental data. Modulation of SCN output at the SPZ was found to generate a full spectrum of diurnal-to-nocturnal phenotypes. Intriguingly, we also uncovered a novel mechanism for crepuscular behavior: if DMH/VLPO and DMH/LHA projections act cooperatively, daily activity is unimodal, but if they act competitively, activity can become bimodal. In addition, we successfully reproduced diurnal/nocturnal switching in the rodent Octodon degu using coordinated inversions in both masking and circadian modulation. Finally, the model correctly predicted the SCN lesion phenotype in squirrel monkeys: loss of circadian rhythmicity and emergence of ∼4-h sleep/wake cycles. In capturing these diverse phenotypes, the model provides a powerful new framework for understanding rest/activity patterns and relating them to underlying physiology. Given the ubiquitous effects of temporal organization on all aspects of animal behavior and physiology, this study sheds light on the physiological changes required to orchestrate adaptation to various temporal niches.
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Sturm A, Czisch M, Spoormaker VI. Effects of unconditioned stimulus intensity and fear extinction on subsequent sleep architecture in an afternoon nap. J Sleep Res 2013; 22:648-55. [DOI: 10.1111/jsr.12074] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Accepted: 06/23/2013] [Indexed: 11/28/2022]
Affiliation(s)
- Anna Sturm
- Max Planck Institute of Psychiatry; Munich Germany
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Stephenson R, Lim J, Famina S, Caron AM, Dowse HB. Sleep-wake behavior in the rat: ultradian rhythms in a light-dark cycle and continuous bright light. J Biol Rhythms 2013; 27:490-501. [PMID: 23223374 DOI: 10.1177/0748730412461247] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Ultradian rhythms are a prominent but little-studied feature of mammalian sleep-wake and rest-activity patterns. They are especially evident in long-term records of behavioral state in polyphasic animals such as rodents. However, few attempts have been made to incorporate ultradian rhythmicity into models of sleep-wake dynamics, and little is known about the physiological mechanisms that give rise to ultradian rhythms in sleep-wake state. This study investigated ultradian dynamics in sleep and wakefulness in rats entrained to a 12-h:12-h light-dark cycle (LD) and in rats whose circadian rhythms were suppressed and free-running following long-term exposure to uninterrupted bright light (LL). We recorded sleep-wake state continuously for 7 to 12 consecutive days and used time-series analysis to quantify the dynamics of net cumulative time in each state (wakefulness [WAKE], rapid eye movement sleep [REM], and non-REM sleep [NREM]) in each animal individually. Form estimates and autocorrelation confirmed the presence of significant ultradian and circadian rhythms; maximum entropy spectral analysis allowed high-resolution evaluation of multiple periods within the signal, and wave-by-wave analysis enabled a statistical evaluation of the instantaneous period, peak-trough range, and phase of each ultradian wave in the time series. Significant ultradian periodicities were present in all 3 states in all animals. In LD, ultradian range was approximately 28% of circadian range. In LL, ultradian range was slightly reduced relative to LD, and circadian range was strongly attenuated. Ultradian rhythms were found to be quasiperiodic in both LD and LL. That is, ultradian period varied randomly around a mean of approximately 4 h, with no relationship between ultradian period and time of day.
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Lima SL, O'Keefe JM. Do predators influence the behaviour of bats? Biol Rev Camb Philos Soc 2013; 88:626-44. [PMID: 23347323 DOI: 10.1111/brv.12021] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 12/18/2012] [Accepted: 12/20/2012] [Indexed: 11/29/2022]
Abstract
Many aspects of animal behaviour are affected by real-time changes in the risk of predation. This conclusion holds for virtually all taxa and ecological systems studied, but does it hold for bats? Bats are poorly represented in the literature on anti-predator behaviour, which may reflect a lack of nocturnal predators specialized on bats. If bats actually experience a world with minimal anti-predator concerns, then they will provide a unique contrast within the realm of vertebrate ecology. Alternatively, such predator-driven behaviour in bats may not yet be fully understood, given the difficulties in working with these highly mobile and nocturnal animals. We provide a wide-ranging exploration of these issues in bat behaviour. We first cover the basic predator-prey information available on bats, both on potential predators and the ways in which bats might perceive predators and respond to attacks. We then cover work relevant to key aspects of bat behaviour, such as choice of daytime roosts, the nature of sleep and torpor, evening roost departures, moonlight avoidance, landscape-related movement patterns, and habitat selection. Overall, the evidence in favour of a strong influence of predators on bat behaviour is equivocal, with the picture clouded by contradictory results and a lack of information on potential predators and the perception of risk by bats. It seems clear that day-active bats run a considerable risk of being killed by diurnal raptors, which are able to capture bats with relative ease. Thus, bats taking advantage of a pulse of insects just prior to sunset are likely taking risks to gain much-needed energy. Further, the choice of daytime roosts by bats is probably strongly influenced by roost safety. Few studies, however, have directly addressed either of these topics. As a group, insectivorous temperate-zone bats show no clear tendency to avoid apparently risky situations, such as activity on moonlit nights. However, some observations are consistent with the idea that predation risk affects choice of movement paths and feeding areas by temperate-zone bats, as well as the timing of roost departures. The behaviour of tropical bats, on the other hand, seems more generally influenced by predators; this is especially true for tropical nectarivores and frugivores, but also for insectivorous bats. Presumably there are more serious predators on bats in the tropics (e.g. specialized raptors or carnivorous bats), but the identity of these predators is unclear. More information is needed to assess fully the influence of predators on bat behaviour. There is much need for work on the ways in which bats perceive predators via auditory, visual, and olfactory cues, and whether bats have some knowledge of the risks posed by different predators. Also needed is information on how predators attack bats and how bats react to attacking predators. Difficult to obtain, but of critical value, will be information on the nature of the predation risk experienced by bats while away from roosts and during the full darkness of night.
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Affiliation(s)
- Steven L Lima
- Department of Biology, Indiana State University, Terre Haute, IN 47809, USA.
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Scriba MF, Harmening WM, Mettke-Hofmann C, Vyssotski AL, Roulin A, Wagner H, Rattenborg NC. Evaluation of two minimally invasive techniques for electroencephalogram recording in wild or freely behaving animals. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2012. [PMID: 23207908 DOI: 10.1007/s00359-012-0779-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Insight into the function of sleep may be gained by studying animals in the ecological context in which sleep evolved. Until recently, technological constraints prevented electroencephalogram (EEG) studies of animals sleeping in the wild. However, the recent development of a small recorder (Neurologger 2) that animals can carry on their head permitted the first recordings of sleep in nature. To facilitate sleep studies in the field and to improve the welfare of experimental animals, herein, we test the feasibility of using minimally invasive surface and subcutaneous electrodes to record the EEG in barn owls. The EEG and behaviour of four adult owls in captivity and of four chicks in a nest box in the field were recorded. We scored a 24-h period for each adult bird for wakefulness, slow-wave sleep (SWS), and rapid-eye movement (REM) sleep using 4 s epochs. Although the quality and stability of the EEG signals recorded via subcutaneous electrodes were higher when compared to surface electrodes, the owls' state was readily identifiable using either electrode type. On average, the four adult owls spent 13.28 h awake, 9.64 h in SWS, and 1.05 h in REM sleep. We demonstrate that minimally invasive methods can be used to measure EEG-defined wakefulness, SWS, and REM sleep in owls and probably other animals.
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Affiliation(s)
- M F Scriba
- Avian Sleep Group, Max Planck Institute for Ornithology, Eberhard-Gwinner-str. 11, 82319, Seewiesen, Germany.
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Gravett N, Bhagwandin A, Lyamin OI, Siegel JM, Manger PR. Sleep in the rock hyrax, Procavia capensis. BRAIN, BEHAVIOR AND EVOLUTION 2012; 79:155-69. [PMID: 22301688 DOI: 10.1159/000335342] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2011] [Accepted: 05/13/2011] [Indexed: 11/19/2022]
Abstract
We investigated sleep in therock hyrax, Procavia capensis, a social mammal that typically lives in colonies on rocky outcrops throughout most parts of Southern Africa. The sleep of 5 wild-captured, adult rock hyraxes was recorded continuously for 72 h using telemetric relay of signals and allowing unimpeded movement. In addition to waking, slow wave sleep (SWS) and an unambiguous rapid eye movement (REM) state, a sleep state termed somnus innominatus (SI), characterized by low-voltage, high-frequency electroencephalogram, an electromyogram that stayed at the same amplitude as the preceding SWS episode and a mostly regular heart rate, were identified. If SI can be considered a form of low-voltage non-REM, the implication would be that the rock hyrax exhibits the lowest amount of REM recorded for any terrestrial mammal studied to date. Conversely, if SI is a form of REM sleep, it would lead to the classification of a novel subdivision of this state; however, further investigation would be required. The hyraxes spent on average 15.89 h (66.2%) of the time awake, 6.02 h (25.1%) in SWS, 43 min (3%) in SI and 6 min (0.4%) in REM. The unambiguous REM sleep amounts were on average less than 6 min/day. The most common state transition pathway in these animals was found to be wake → SWS → wake. No significant differences were noted with regard to total sleep time, number of episodes and episode duration for all states between the light and dark periods.Thus, prior classification of the rock hyrax as strongly diurnal does not appear to hold under controlled laboratory conditions.
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Affiliation(s)
- Nadine Gravett
- School of Anatomical Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Amo L, Caro SP, Visser ME. Sleeping birds do not respond to predator odour. PLoS One 2011; 6:e27576. [PMID: 22110676 PMCID: PMC3217974 DOI: 10.1371/journal.pone.0027576] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Accepted: 10/19/2011] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND During sleep animals are relatively unresponsive and unaware of their environment, and therefore, more exposed to predation risk than alert and awake animals. This vulnerability might influence when, where and how animals sleep depending on the risk of predation perceived before going to sleep. Less clear is whether animals remain sensitive to predation cues when already asleep. METHODOLOGY/PRINCIPAL FINDINGS We experimentally tested whether great tits are able to detect the chemical cues of a common nocturnal predator while sleeping. We predicted that birds exposed to the scent of a mammalian predator (mustelid) twice during the night would not go into torpor (which reduces their vigilance) and hence would not reduce their body temperature as much as control birds, exposed to the scent of another mammal that does not represent a danger for the birds (rabbit). As a consequence of the higher body temperature birds exposed to the scent of a predator are predicted to have a higher resting metabolic rate (RMR) and to lose more body mass. In the experiment, all birds decreased their body temperature during the night, but we did not find any influence of the treatment on body temperature, RMR, or body mass. CONCLUSIONS/SIGNIFICANCE Our results suggest that birds are not able to detect predator chemical cues while sleeping. As a consequence, antipredatory strategies taken before sleep, such as roosting sites inspection, may be crucial to cope with the vulnerability to predation risk while sleeping.
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Affiliation(s)
- Luisa Amo
- Department of Animal Ecology, Netherlands Institute of Ecology, Wageningen, The Netherlands.
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Spoormaker VI, Schröter MS, Andrade KC, Dresler M, Kiem SA, Goya-Maldonado R, Wetter TC, Holsboer F, Sämann PG, Czisch M. Effects of rapid eye movement sleep deprivation on fear extinction recall and prediction error signaling. Hum Brain Mapp 2011; 33:2362-76. [PMID: 21826762 DOI: 10.1002/hbm.21369] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Revised: 04/01/2011] [Accepted: 05/02/2011] [Indexed: 02/05/2023] Open
Abstract
In a temporal difference learning approach of classical conditioning, a theoretical error signal shifts from outcome deliverance to the onset of the conditioned stimulus. Omission of an expected outcome results in a negative prediction error signal, which is the initial step towards successful extinction and may therefore be relevant for fear extinction recall. As studies in rodents have observed a bidirectional relationship between fear extinction and rapid eye movement (REM) sleep, we aimed to test the hypothesis that REM sleep deprivation impairs recall of fear extinction through prediction error signaling in humans. In a three-day design with polysomnographically controlled REM sleep deprivation, 18 young, healthy subjects performed a fear conditioning, extinction and recall of extinction task with visual stimuli, and mild electrical shocks during combined functional magnetic resonance imaging (fMRI) and skin conductance response (SCR) measurements. Compared to the control group, the REM sleep deprivation group had increased SCR scores to a previously extinguished stimulus at early recall of extinction trials, which was associated with an altered fMRI time-course in the left middle temporal gyrus. Post-hoc contrasts corrected for measures of NREM sleep variability also revealed between-group differences primarily in the temporal lobe. Our results demonstrate altered prediction error signaling during recall of fear extinction after REM sleep deprivation, which may further our understanding of anxiety disorders in which disturbed sleep and impaired fear extinction learning coincide. Moreover, our findings are indicative of REM sleep related plasticity in regions that also show an increase in activity during REM sleep.
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Affiliation(s)
- Victor I Spoormaker
- Max Planck Institute of Psychiatry, Kraepelinstrasse 2-10, 80804 Munich, Germany.
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The neural correlates and temporal sequence of the relationship between shock exposure, disturbed sleep and impaired consolidation of fear extinction. J Psychiatr Res 2010; 44:1121-8. [PMID: 20471033 DOI: 10.1016/j.jpsychires.2010.04.017] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 04/16/2010] [Accepted: 04/16/2010] [Indexed: 11/22/2022]
Abstract
Consolidation of extinction learning is a primary mechanism disrupted in posttraumatic stress disorder (PTSD), associated with hypoactivity of the ventromedial prefrontal cortex and hippocampus. A role for rapid eye movement (REM) sleep disturbances in this failure to consolidate extinction learning has been proposed. We performed functional magnetic resonance imaging (fMRI) with simultaneous skin conductance response (SCR) measurements in 16 healthy participants during conditioning/extinction and later recall of extinction. The visual stimuli were basic geometric forms and electrical shocks functioned as the unconditioned stimulus. Between the conditioning/extinction and recall sessions, participants received a 90-min sleep window in the sleep laboratory. This daytime sleep was polysomnographically recorded and scored by professionals blind to the study design. Only seven out of 16 participants had REM sleep; participants without REM sleep had a significantly slower decline of both SCR and neural activity of the laterodorsal tegmentum in response to electrical shocks during conditioning. At recall of fear extinction, participants with preceding REM sleep had a reduced SCR and stronger activation of the left ventromedial prefrontal cortex and bilateral lingual gyrus in response to the extinguished stimulus than participants lacking REM sleep. This study indicates that trait-like differences in shock reactivity/habituation (mediated by the brainstem) are predictive of REM sleep disruption, which in turn is associated with impaired consolidation of extinction (mediated by the ventromedial prefrontal cortex). These findings help understand the neurobiological basis and the temporal sequence of the relationship between shock exposure, disturbed sleep and impaired consolidation of extinction, as observed in PTSD.
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Sanford LD, Yang L, Wellman LL, Liu X, Tang X. Differential effects of controllable and uncontrollable footshock stress on sleep in mice. Sleep 2010; 33:621-30. [PMID: 20469804 DOI: 10.1093/sleep/33.5.621] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Inescapable shock (IS), an uncontrollable stressor, and presentation of fearful contexts associated with IS produce prominent reductions in REM sleep. We compared sleep in animals trained with IS to that in animals trained with escapable shock (ES), a controllable stressor, in a paradigm in which animals always received shock but could terminate it by their actions. DESIGN Male BALB/cJ mice were implanted with telemetry transmitters for recording EEG and activity. After recovery from surgery, baseline sleep recordings were obtained for 2 days. The mice were then randomly assigned to receive ES (n=9) or IS (n=9). ES mice could escape a footshock (20 trials; 0.5 mA; 5.0 sec maximum duration; 1.0 min intervals) by moving to the unoccupied chamber in a shuttlebox. Yoked-control IS mice in a separate shuttlebox received identical footshock. The mice received 2 days of shock training (ST1; ST2) and were re-exposed to the shuttlebox without footshock (context alone). SETTING NA. PATIENTS OR PARTICIPANTS NA. INTERVENTIONS NA. MEASUREMENTS AND RESULTS On each training and test day, the mice were returned to their home cages, and EEG and activity were recorded for 20 h. Freezing was scored in the context alone. Compared to baseline, ES mice showed significantly increased REM, and IS mice showed significantly decreased REM after ST1, ST2, and context alone. Total NREM was decreased after shock training only in IS mice. Contextual freezing was enhanced in both ES and IS mice. CONCLUSIONS The directionally opposite changes in REM suggest that stressor controllability is an important factor in the effects of stress and stressful memories on sleep.
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Affiliation(s)
- Larry D Sanford
- Sleep Research Laboratory, Department of Pathology and Anatomy, Eastern Virginia Medical School, P.O. Box 1980, Norfolk, VA 23501, USA.
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Roth TC, Rattenborg NC, Pravosudov VV. The ecological relevance of sleep: the trade-off between sleep, memory and energy conservation. Philos Trans R Soc Lond B Biol Sci 2010; 365:945-59. [PMID: 20156818 PMCID: PMC2830243 DOI: 10.1098/rstb.2009.0209] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
All animals in which sleep has been studied express signs of sleep-like behaviour, suggesting that sleep must have some fundamental functions that are sustained by natural selection. Those functions, however, are still not clear. Here, we examine the ecological relevance of sleep from the perspective of behavioural trade-offs that might affect fitness. Specifically, we highlight the advantage of using food-caching animals as a system in which a conflict might occur between engaging in sleep for memory/learning and hypothermia/torpor to conserve energy. We briefly review the evidence for the importance of sleep for memory, the importance of memory for food-caching animals and the conflicts that might occur between sleep and energy conservation in these animals. We suggest that the food-caching paradigm represents a naturalistic and experimentally practical system that provides the opportunity for a new direction in sleep research that will expand our understanding of sleep, especially within the context of ecological and evolutionary processes.
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Affiliation(s)
- Timothy C Roth
- Department of Biology, University of Nevada, Reno, NV 89557, USA.
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Yang L, Tang X, Wellman LL, Liu X, Sanford LD. Corticotropin releasing factor (CRF) modulates fear-induced alterations in sleep in mice. Brain Res 2009; 1276:112-22. [PMID: 19376095 DOI: 10.1016/j.brainres.2009.04.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2008] [Revised: 04/06/2009] [Accepted: 04/10/2009] [Indexed: 12/30/2022]
Abstract
Contextual fear significantly reduces rapid eye movement sleep (REM) during post-exposure sleep in mice and rats. Corticotropin releasing factor (CRF) plays a major role in CNS responses to stressors. We examined the influence of CRF and astressin (AST), a non-specific CRF antagonist, on sleep after contextual fear in BALB/c mice. Male mice were implanted with transmitters for recording sleep via telemetry and with a guide cannula aimed into the lateral ventricle. Recordings for vehicle and handling control were obtained after ICV microinjection of saline (SAL) followed by exposure to a novel chamber. Afterwards, the mice were subjected to shock training (20 trials, 0.5 mA, 0.5 s duration) for 2 sessions. After training, separate groups of mice received ICV microinjections of SAL (0.2 microl, n=9), CRF (0.4 microg, n=8), or AST (1.0 microg, n=8) prior to exposure to the shock context alone. Sleep was then recorded for 20 h (8-hour light and 12-hour dark period). Compared to handling control, contextual fear significantly decreased REM during the 8-h light period in mice receiving SAL and in mice receiving CRF, but not in the mice receiving AST. Mice receiving CRF exhibited reductions in REM during the 12-h dark period after contextual fear, whereas mice receiving SAL or AST did not. CRF also reduced non-REM (NREM) delta (slow wave) amplitude in the EEG. Only mice receiving SAL prior to contextual fear exhibited significant reductions in NREM and total sleep. These findings demonstrate a role for the central CRF system in regulating alterations in sleep induced by contextual fear.
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Affiliation(s)
- Linghui Yang
- Sleep Research Laboratory, Department of Pathology and Anatomy, Eastern Virginia Medical School, P.O. Box 1980, Norfolk, VA 23501, USA
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Capellini I, Nunn CL, McNamara P, Preston BT, Barton RA. Energetic constraints, not predation, influence the evolution of sleep patterning in mammals. Funct Ecol 2008; 22:847-853. [PMID: 20428321 PMCID: PMC2860325 DOI: 10.1111/j.1365-2435.2008.01449.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Mammalian sleep is composed of two distinct states - rapid-eye-movement (REM) and non-REM (NREM) sleep - that alternate in cycles over a sleep bout. The duration of these cycles varies extensively across mammalian species. Because the end of a sleep cycle is often followed by brief arousals to waking, a shorter sleep cycle has been proposed to function as an anti-predator strategy. Similarly, higher predation risk could explain why many species exhibit a polyphasic sleep pattern (division of sleep into several bouts per day), as having multiple sleep bouts avoids long periods of unconsciousness, potentially reducing vulnerability.Using phylogenetic comparative methods, we tested these predictions in mammals, and also investigated the relationships among sleep phasing, sleep-cycle length, sleep durations and body mass.Neither sleep-cycle length nor phasing of sleep was significantly associated with three different measures of predation risk, undermining the idea that they represent anti-predator adaptations.Polyphasic sleep was associated with small body size, shorter sleep cycles and longer sleep durations. The correlation with size may reflect energetic constraints: small animals need to feed more frequently, preventing them from consolidating sleep into a single bout. The reduced daily sleep quotas in monophasic species suggests that the consolidation of sleep into one bout per day may deliver the benefits of sleep more efficiently and, since early mammals were small-bodied and polyphasic, a more efficient monophasic sleep pattern could be a hitherto unrecognized advantage of larger size.
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Affiliation(s)
- I. Capellini
- Evolutionary Anthropology Research Group, Department of Anthropology, Durham University, County Durham DH1 3HN, UK
| | - C. L. Nunn
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz No 6, D-04103 Leipzig, Germany
- Department of Integrative Biology, University of California, Berkeley, CA 94720, USA
| | - P. McNamara
- Department of Neurology, Boston University School of Medicine and VA New England Healthcare System, Boston, MA 02130, USA
| | - B. T. Preston
- Max Planck Institute for Evolutionary Anthropology, Deutscher Platz No 6, D-04103 Leipzig, Germany
| | - R. A. Barton
- Evolutionary Anthropology Research Group, Department of Anthropology, Durham University, County Durham DH1 3HN, UK
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