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Lesku JA, Libourel PA, Kelly ML, Hemmi JM, Kerr CC, Collin SP, Radford CA. An electrophysiological correlate of sleep in a shark. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 38957102 DOI: 10.1002/jez.2846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/04/2024]
Abstract
Sleep is a prominent physiological state observed across the animal kingdom. Yet, for some animals, our ability to identify sleep can be masked by behaviors otherwise associated with being awake, such as for some sharks that must swim continuously to push oxygenated seawater over their gills to breathe. We know that sleep in buccal pumping sharks with clear rest/activity cycles, such as draughtsboard sharks (Cephaloscyllium isabellum, Bonnaterre, 1788), manifests as a behavioral shutdown, postural relaxation, reduced responsiveness, and a lowered metabolic rate. However, these features of sleep do not lend themselves well to animals that swim nonstop. In addition to video and accelerometry recordings, we tried to explore the electrophysiological correlates of sleep in draughtsboard sharks using electroencephalography (EEG), electromyography, and electrooculography, while monitoring brain temperature. The seven channels of EEG activity had a surprising level of (apparent) instability when animals were swimming, but also when sleeping. The amount of stable EEG signals was too low for replication within- and across individuals. Eye movements were not measurable, owing to instability of the reference electrode. Based on an established behavioral characterization of sleep in draughtsboard sharks, we offer the original finding that muscle tone was strongest during active wakefulness, lower in quietly awake sharks, and lowest in sleeping sharks. We also offer several critical suggestions on how to improve techniques for characterizing sleep electrophysiology in future studies on elasmobranchs, particularly for those that swim continuously. Ultimately, these approaches will provide important insights into the evolutionary confluence of behaviors typically associated with wakefulness and sleep.
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Affiliation(s)
- John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
| | - Paul-Antoine Libourel
- Center for Functional and Evolutionary Ecology, MAD Team, Montpellier, France
- Neuroscience Research Center of Lyon, Sleep Team, Bron, France
| | - Michael L Kelly
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
- Australian Centre for Disease Preparedness, Commonwealth Scientific and Industrial Research Organisation, Geelong, Victoria, Australia
| | - Jan M Hemmi
- School of Biological Sciences, The University of Western Australia, Perth, Western Australia, Australia
- Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Caroline C Kerr
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
| | - Shaun P Collin
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, Victoria, Australia
- Oceans Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Craig A Radford
- Institute of Marine Science, Leigh Marine Laboratory, The University of Auckland, Auckland, New Zealand
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2
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Sharon O, Ben Simon E, Shah VD, Desel T, Walker MP. The new science of sleep: From cells to large-scale societies. PLoS Biol 2024; 22:e3002684. [PMID: 38976664 PMCID: PMC11230563 DOI: 10.1371/journal.pbio.3002684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/10/2024] Open
Abstract
In the past 20 years, more remarkable revelations about sleep and its varied functions have arguably been made than in the previous 200. Building on this swell of recent findings, this essay provides a broad sampling of selected research highlights across genetic, molecular, cellular, and physiological systems within the body, networks within the brain, and large-scale social dynamics. Based on this raft of exciting new discoveries, we have come to realize that sleep, in this moment of its evolution, is very much polyfunctional (rather than monofunctional), yet polyfunctional for reasons we had never previously considered. Moreover, these new polyfunctional insights powerfully reaffirm sleep as a critical biological, and thus health-sustaining, requisite. Indeed, perhaps the only thing more impressive than the unanticipated nature of these newly emerging sleep functions is their striking divergence, from operations of molecular mechanisms inside cells to entire group societal dynamics.
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Affiliation(s)
- Omer Sharon
- Department of Psychology, University of California, Berkeley, California, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Eti Ben Simon
- Department of Psychology, University of California, Berkeley, California, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Vyoma D. Shah
- Department of Psychology, University of California, Berkeley, California, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Tenzin Desel
- Department of Psychology, University of California, Berkeley, California, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
| | - Matthew P. Walker
- Department of Psychology, University of California, Berkeley, California, United States of America
- Helen Wills Neuroscience Institute, University of California, Berkeley, California, United States of America
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3
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Joyce M, Falconio FA, Blackhurst L, Prieto-Godino L, French AS, Gilestro GF. Divergent evolution of sleep in Drosophila species. Nat Commun 2024; 15:5091. [PMID: 38876988 PMCID: PMC11178934 DOI: 10.1038/s41467-024-49501-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 06/05/2024] [Indexed: 06/16/2024] Open
Abstract
Living organisms synchronize their biological activities with the earth's rotation through the circadian clock, a molecular mechanism that regulates biology and behavior daily. This synchronization factually maximizes positive activities (e.g., social interactions, feeding) during safe periods, and minimizes exposure to dangers (e.g., predation, darkness) typically at night. Beyond basic circadian regulation, some behaviors like sleep have an additional layer of homeostatic control, ensuring those essential activities are fulfilled. While sleep is predominantly governed by the circadian clock, a secondary homeostatic regulator, though not well-understood, ensures adherence to necessary sleep amounts and hints at a fundamental biological function of sleep beyond simple energy conservation and safety. Here we explore sleep regulation across seven Drosophila species with diverse ecological niches, revealing that while circadian-driven sleep aspects are consistent, homeostatic regulation varies significantly. The findings suggest that in Drosophilids, sleep evolved primarily for circadian purposes. The more complex, homeostatically regulated functions of sleep appear to have evolved independently in a species-specific manner, and are not universally conserved. This laboratory model may reproduce and recapitulate primordial sleep evolution.
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Affiliation(s)
- Michaela Joyce
- Department of Life Sciences, Imperial College London, London, UK
- The Francis Crick Research Institute, London, UK
| | | | | | | | - Alice S French
- Department of Life Sciences, Imperial College London, London, UK.
- The Francis Crick Research Institute, London, UK.
- School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK.
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4
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Kruger JL, Bhagwandin A, Katandukila JV, Bennett NC, Manger PR. Sleep in the East African root rat, Tachyoryctes splendens. JOURNAL OF EXPERIMENTAL ZOOLOGY. PART A, ECOLOGICAL AND INTEGRATIVE PHYSIOLOGY 2024. [PMID: 38828695 DOI: 10.1002/jez.2839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 05/16/2024] [Accepted: 05/16/2024] [Indexed: 06/05/2024]
Abstract
The present study reports the results of an electrophysiological analysis of sleep in the East African root rat, Tachyoryctes splendens, belonging to the rodent subfamily Spalacinae. Telemetric electroencephalographic (EEG) and electromyographic recordings, with associated video recording, on three root rats over a continuous 72 h period (12 h light/12 h dark cycle) were analyzed. The analysis revealed that the East African root rat has a total sleep time (TST) of 8.9 h per day. Despite this relatively short total sleep time in comparison to fossorial rodents, nonrapid eye movement (non-REM) sleep and rapid eye movement (REM) sleep states showed similar physiological signatures to that observed in other rodents and no unusual sleep states were observed. REM occupied 19.7% of TST, which is within the range observed in other rodents. The root rats were extremely active during the dark period, and appeared to spend much of the light period in quiet wake while maintaining vigilance (as determined from both EEG recordings and behavioral observation). These recordings were made under normocapnic environmental conditions, which contrasts with the hypercapnic environment of their natural burrows.
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Affiliation(s)
- Jean-Leigh Kruger
- 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
| | - Jestina V Katandukila
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
- Department of Zoology and Wildlife Conservation, University of Dar es Salaam, Dar es Salaam, Tanzania
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Lyamin OI, Borshchenko VD, Siegel JM. A 108-h total sleep deprivation did not impair fur seal performance in delayed matching to sample task. J Comp Physiol B 2024; 194:315-333. [PMID: 37596419 PMCID: PMC11296610 DOI: 10.1007/s00360-023-01511-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/05/2023] [Accepted: 08/07/2023] [Indexed: 08/20/2023]
Abstract
While the majority of studies have concluded that sleep deprivation causes detrimental effects on various cognitive processes, some studies reported conflicting results. We examined the effects of a 108-h total sleep deprivation (TSD) on working memory in the northern fur seal, an animal with unusual sleep phenomenology and long-range annual migrations. The performance of fur seals was evaluated in a two-choice visual delayed matching to sample (DMTS) task, which is commonly used to evaluate working memory. In baseline conditions, the performance of fur seals in a DMTS task based on the percentage of errors was somewhat comparable with that in nonhuman primates at similar delays. We have determined that a 108-h TSD did not affect fur seals' performance in a visual DMTS task as measured by overall percentage of errors and response latencies. On the contrary, all fur seals improved task performance over the study, including the baseline, TSD and recovery conditions. In addition, TSD did not change the direction and strength of the pattern of behavioral lateralization in fur seals. We conclude that a 108-h TSD did not interfere with working memory in a DMTS test in northern fur seals.
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Affiliation(s)
- Oleg I Lyamin
- Department of Psychiatry, University of California Los Angeles, Center for Sleep Research, 16111 Plummer St, North Hills, Los Angeles, CA, 91343, USA.
- A.N. Severtsov Institute of Ecology and Evolution, Moscow, Russia.
| | - Vasilisa D Borshchenko
- I.M. Sechenov Institute of Evolutionary Physiology and Biochemistry, St Petersburg, Russia
| | - Jerome M Siegel
- Department of Psychiatry, University of California Los Angeles, Center for Sleep Research, 16111 Plummer St, North Hills, Los Angeles, CA, 91343, USA
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Reinitz LZ, Lenzing F, Papp E, Biácsi A, Fajtai D, Petneházy Ö. CT reconstruction based 3D model of the digital cushion's blood supply in the hind foot of an African savanna elephant ( Loxodonta africana). Front Vet Sci 2024; 11:1399392. [PMID: 38803804 PMCID: PMC11128542 DOI: 10.3389/fvets.2024.1399392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 04/23/2024] [Indexed: 05/29/2024] Open
Abstract
Introduction Foot health is crucial for elephants, as pathological lesions of the feet are a leading cause of euthanasia in captive elephants, which are endangered species. Proper treatment of the feet, particularly in conditions affecting the digits and the digital cushion, requires a thorough understanding of the underlying anatomy. However, only limited literature exists due to the small population and the epidemiological foot diseases which often precludes many deceased elephants from scientific study. The aim of this study was to provide a detailed anatomical description of the blood supply to the African elephant's hindfoot. Methods The healthy right hindlimb of a 19-year-old deceased female African savanna elephant was examined using computed tomography. Following a native sequence, 48 mL of barium-based contrast agent was injected into the caudal and cranial tibial arteries, and a subsequent scan was performed. The images were processed with 3D Slicer software. Results The medial and lateral plantar arteries run in a symmetrical pattern. They each have a dorsal and a plantar branch, which reach the plantar skin before turning toward the axial plane of the sole to reach the digital cushion from the proximal direction. An accurate 3D model of the arteries and the bones of the foot, a set of labeled images and an animation of the blood supply have been created for ease of understanding. Discussion In contrast to domestic ungulates, the digital cushion of the hindlimb is supplied differently from that of the forelimb. The lack of large vessels in its deeper layers indicates a slow regeneration time. This novel anatomical information may be useful in the planning of surgical interventions and in emergency medical procedures.
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Affiliation(s)
- László Zoltán Reinitz
- Department of Anatomy and Histology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Franka Lenzing
- Department of Anatomy and Histology, University of Veterinary Medicine Budapest, Budapest, Hungary
| | - Endre Papp
- Nyíregyházi Állatpark Nonprofit Kft. (Sosto Zoo), Nyíregyháza, Hungary
| | - Alexandra Biácsi
- Nyíregyházi Állatpark Nonprofit Kft. (Sosto Zoo), Nyíregyháza, Hungary
| | - Dániel Fajtai
- Medicopus Nonprofit Ltd., Kaposvár, Hungary
- Institute of Animal Physiology and Nutrition, Department of Physiology and Animal Health, Hungarian University of Agriculture and Life Sciences, Kaposvár, Hungary
| | - Örs Petneházy
- Medicopus Nonprofit Ltd., Kaposvár, Hungary
- Institute of Animal Physiology and Nutrition, Department of Physiology and Animal Health, Hungarian University of Agriculture and Life Sciences, Kaposvár, Hungary
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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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8
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Cox DTC, Gaston KJ. Cathemerality: a key temporal niche. Biol Rev Camb Philos Soc 2024; 99:329-347. [PMID: 37839797 DOI: 10.1111/brv.13024] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 10/01/2023] [Accepted: 10/02/2023] [Indexed: 10/17/2023]
Abstract
Given the marked variation in abiotic and biotic conditions between day and night, many species specialise their physical activity to being diurnal or nocturnal, and it was long thought that these strategies were commonly fairly fixed and invariant. The term 'cathemeral', was coined in 1987, when Tattersall noted activity in a Madagascan primate during the hours of both daylight and darkness. Initially thought to be rare, cathemerality is now known to be a quite widespread form of time partitioning amongst arthropods, fish, birds, and mammals. Herein we provide a synthesis of present understanding of cathemeral behaviour, arguing that it should routinely be included alongside diurnal and nocturnal strategies in schemes that distinguish and categorise species across taxa according to temporal niche. This synthesis is particularly timely because (i) the study of animal activity patterns is being revolutionised by new and improved technologies; (ii) it is becoming apparent that cathemerality covers a diverse range of obligate to facultative forms, each with their own common sets of functional traits, geographic ranges and evolutionary history; (iii) daytime and nighttime activity likely plays an important but currently neglected role in temporal niche partitioning and ecosystem functioning; and (iv) cathemerality may have an important role in the ability of species to adapt to human-mediated pressures.
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Affiliation(s)
- Daniel T C Cox
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
| | - Kevin J Gaston
- Environment and Sustainability Institute, University of Exeter, Penryn, Cornwall, TR10 9FE, UK
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9
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Fjell AM, Walhovd KB. Individual sleep need is flexible and dynamically related to cognitive function. Nat Hum Behav 2024; 8:422-430. [PMID: 38379065 DOI: 10.1038/s41562-024-01827-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 01/15/2024] [Indexed: 02/22/2024]
Abstract
Given that sleep deprivation studies consistently show that short sleep causes neurocognitive deficits, the effects of insufficient sleep on brain health and cognition are of great interest and concern. Here we argue that experimentally restricted sleep is not a good model for understanding the normal functions of sleep in naturalistic settings. Cross-disciplinary research suggests that human sleep is remarkably dependent on environmental conditions and social norms, thus escaping universally applicable rules. Sleep need varies over time and differs between individuals, showing a complex relationship with neurocognitive function. This aspect of sleep is rarely addressed in experimental work and is not reflected in expert recommendations about sleep duration. We recommend focusing on the role of individual and environmental factors to improve our understanding of the relationship between human sleep and cognition.
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Affiliation(s)
- Anders M Fjell
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway.
- Center for Computational Radiology and Artificial Intelligence, Oslo University Hospital, Oslo, Norway.
| | - Kristine B Walhovd
- Center for Lifespan Changes in Brain and Cognition, University of Oslo, Oslo, Norway
- Center for Computational Radiology and Artificial Intelligence, Oslo University Hospital, Oslo, Norway
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10
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Grenfell KL, Jacobs PJ, Bennett NC, Hart DW. The role of ambient temperature and light as cues in the control of circadian rhythms of Damaraland mole-rat. Chronobiol Int 2024; 41:356-368. [PMID: 38444071 DOI: 10.1080/07420528.2024.2325649] [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: 11/08/2023] [Accepted: 02/27/2024] [Indexed: 03/07/2024]
Abstract
Light is considered the primary entrainer for mammalian biological rhythms, including locomotor activity (LA). However, mammals experience different environmental and light conditions, which include those predominantly devoid of light stimuli, such as those experienced in subterranean environments. In this study, we investigated what environmental cue (light or ambient temperature (Ta)) is the strongest modulator of circadian rhythms, by using LA as a proxy, in mammals that experience a lifestyle devoid of light stimuli. To address this question, this study exposed a subterranean African mole-rat species, the Damaraland mole-rat (Fukomys damarensis), to six light and Ta cycles in different combinations. Contrary to previous literature, when provided with a reliable light cue, Damaraland mole rats exhibited nocturnal, diurnal, or arrhythmic LA patterns under constant Ta. While under constant darkness and a 24-hour Ta cycle mimicking the burrow environment, all mole-rats were most active during the coolest 12-hour period. This finding suggests that in a subterranean environment, which receives no reliable photic cue, the limited heat dissipation and energy constraints during digging activity experienced by Damaraland mole-rats make Ta a reliable and consistent "time-keeping" variable. More so, when providing a reliable light cue (12 light: 12 dark) to Damaraland mole-rats under a 24-hour Ta cycle, this study presents the first evidence that cycles of Ta affect the LA rhythm of a subterranean mammal more strongly than cycles of light and darkness. Once again, Damaraland mole-rats were more active during the coolest 12-hour period regardless of whether this fell during the light or dark phase. However, conclusive differentiation of entrainment to Ta from that of masking was not achieved in this study, and as such, we have recommended future research avenues to do so.
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Affiliation(s)
- Kerryn L Grenfell
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
| | - Paul J Jacobs
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
| | - Daniel W Hart
- Department of Zoology and Entomology, University of Pretoria, Hatfield, South Africa
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11
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Zaid E, Rainsford FW, Johnsson RD, Valcu M, Vyssotski AL, Meerlo P, Lesku JA. Semelparous marsupials reduce sleep for sex. Curr Biol 2024; 34:606-614.e3. [PMID: 38278151 DOI: 10.1016/j.cub.2023.12.064] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/16/2023] [Accepted: 12/19/2023] [Indexed: 01/28/2024]
Abstract
Sleep is a prominent, seemingly universal animal behavior. Although sleep maintains optimal waking performance, the biological drive to sleep may be incompatible with the life history of some species. In a multi-year study on semelparous marsupials in Australia, we provide the first direct evidence of ecological sleep restriction in a terrestrial mammal. Dusky (Antechinus swainsonii) and agile (A. agilis) antechinus have an unusual reproductive strategy characterized by the synchronous death of all males at the end of their only breeding season. Using accelerometry, electrophysiology, and metabolomics, we show that males, but not females, increase their activity during the breeding season by reducing sleep. In a trade-off between the neurophysiological requirements for sleep and evolutionary necessity for reproduction, strong sexual selection might drive males to sacrifice sleep to increase access to fertile females and ultimately maximize their fitness.
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Affiliation(s)
- Erika Zaid
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3086, Australia.
| | - Frederick W Rainsford
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3086, Australia
| | - Robin D Johnsson
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3086, Australia; Department of Psychology, Franklin and Marshall College, Lancaster, PA 17603, USA
| | - Mihai Valcu
- Department of Ornithology, Max Planck Institute for Biological Intelligence, 82319 Seewiesen, Germany
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and Swiss Federal Institute of Technology (ETH), 8057 Zurich, Switzerland
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9747 AG, the Netherlands
| | - John A Lesku
- School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3086, Australia.
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12
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Gübert J, Schneider G, Hahn‐Klimroth M, Dierkes PW. Nocturnal behavioral patterns of African ungulates in zoos. Ecol Evol 2023; 13:e10777. [PMID: 38053790 PMCID: PMC10694388 DOI: 10.1002/ece3.10777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 11/08/2023] [Accepted: 11/14/2023] [Indexed: 12/07/2023] Open
Abstract
Currently, most studies on ungulates' behavior are conducted during the daylight hours, but their nocturnal behavior patterns differ from those shown during day. Therefore, it is necessary to observe ungulates' behavior also overnight. Detailed analyses of nocturnal behavior have only been conducted for very prominent ungulates such as Giraffes (Giraffa camelopardalis), African Elephants (Loxodonta africana), or livestock (e.g., domesticated cattle, sheep, or pigs), and the nocturnal rhythms exhibited by many ungulates remain unknown. In the present study, the nocturnal rhythms of 192 individuals of 18 ungulate species from 20 European zoos are studied with respect to the behavioral positions standing, lying-head up, and lying-head down (the typical REM sleep position). Differences between individuals of different age were found, but no differences with respect to the sex were seen. Most species showed a significant increase in the proportion of lying during the night. In addition, the time between two events of "lying down" was studied in detail. A high degree of rhythmicity with respect to this quantity was found in all species. The proportion of lying in such a period was greater in Artiodactyla than in Perissodactyla, and greater in juveniles than in adults.
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Affiliation(s)
- Jennifer Gübert
- Faculty of Biological SciencesGoethe University FrankfurtFrankfurtGermany
| | - Gaby Schneider
- Institute of MathematicsGoethe University FrankfurtFrankfurtGermany
| | | | - Paul W. Dierkes
- Faculty of Biological SciencesGoethe University FrankfurtFrankfurtGermany
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13
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Olejarz A, Faltusová M, Börger L, Güldenpfennig J, Jarský V, Ježek M, Mortlock E, Silovský V, Podgórski T. Worse sleep and increased energy expenditure yet no movement changes in sub-urban wild boar experiencing an influx of human visitors (anthropulse) during the COVID-19 pandemic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 879:163106. [PMID: 36966827 PMCID: PMC10038670 DOI: 10.1016/j.scitotenv.2023.163106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 03/14/2023] [Accepted: 03/23/2023] [Indexed: 05/17/2023]
Abstract
Expansion of urban areas, landscape transformation and increasing human outdoor activities strongly affect wildlife behaviour. The outbreak of the COVID-19 pandemic in particular led to drastic changes in human behaviour, exposing wildlife around the world to either reduced or increased human presence, potentially altering animal behaviour. Here, we investigate behavioural responses of wild boar (Sus scrofa) to changing numbers of human visitors to a suburban forest near Prague, Czech Republic, during the first 2.5 years of the COVID-19 epidemic (April 2019-November 2021). We used bio-logging and movement data of 63 GPS-collared wild boar and human visitation data based on an automatic counter installed in the field. We hypothesised that higher levels of human leisure activity will have a disturbing effect on wild boar behaviour manifested in increased movements and ranging, energy spent, and disrupted sleep patterns. Interestingly, whilst the number of people visiting the forest varied by two orders of magnitude (from 36 to 3431 people weekly), even high levels of human presence (>2000 visitors per week) did not affect weekly distance travelled, home range size, and maximum displacement of wild boar. Instead, individuals spent 41 % more energy at high levels of human presence (>2000 visitors per week), with more erratic sleep patterns, characterised by shorter and more frequent sleeping bouts. Our results highlight multifaceted effects of increased human activities ('anthropulses'), such as those related to COVID-19 countermeasures, on animal behaviour. High human pressure may not affect animal movements or habitat use, especially in highly adaptable species such as wild boar, but may disrupt animal activity rhythms, with potentially detrimental fitness consequences. Such subtle behavioural responses can be overlooked if using only standard tracking technology.
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Affiliation(s)
- 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.
| | - 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
| | - Luca Börger
- Department of Biosciences, Swansea University, Singleton Park, Swansea SA2 8PP, Wales, UK
| | - 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
| | - Vilém Jarský
- Department of Forestry and Wood Economics, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Kamýcká 129, Prague 6-Suchdol, 165 00, Czech Republic
| | - 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
| | - Euan Mortlock
- School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT95DL, Northern Ireland, 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
| | - Tomasz Podgórski
- 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; Mammal Research Institute, Polish Academy of Sciences, Stoczek 1, 17-230 Białowieża, Poland
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14
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Roach ST, Ford MC, Simhambhatla V, Loutrianakis V, Farah H, Li Z, Periandri EM, Abdalla D, Huang I, Kalra A, Shaw PJ. Sleep deprivation, sleep fragmentation, and social jet lag increase temperature preference in Drosophila. Front Neurosci 2023; 17:1175478. [PMID: 37274220 PMCID: PMC10237294 DOI: 10.3389/fnins.2023.1175478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/02/2023] [Indexed: 06/06/2023] Open
Abstract
Despite the fact that sleep deprivation substantially affects the way animals regulate their body temperature, the specific mechanisms behind this phenomenon are not well understood. In both mammals and flies, neural circuits regulating sleep and thermoregulation overlap, suggesting an interdependence that may be relevant for sleep function. To investigate this relationship further, we exposed flies to 12 h of sleep deprivation, or 48 h of sleep fragmentation and evaluated temperature preference in a thermal gradient. Flies exposed to 12 h of sleep deprivation chose warmer temperatures after sleep deprivation. Importantly, sleep fragmentation, which prevents flies from entering deeper stages of sleep, but does not activate sleep homeostatic mechanisms nor induce impairments in short-term memory also resulted in flies choosing warmer temperatures. To identify the underlying neuronal circuits, we used RNAi to knock down the receptor for Pigment dispersing factor, a peptide that influences circadian rhythms, temperature preference and sleep. Expressing UAS-PdfrRNAi in subsets of clock neurons prevented sleep fragmentation from increasing temperature preference. Finally, we evaluated temperature preference after flies had undergone a social jet lag protocol which is known to disrupt clock neurons. In this protocol, flies experience a 3 h light phase delay on Friday followed by a 3 h light advance on Sunday evening. Flies exposed to social jet lag exhibited an increase in temperature preference which persisted for several days. Our findings identify specific clock neurons that are modulated by sleep disruption to increase temperature preference. Moreover, our data indicate that temperature preference may be a more sensitive indicator of sleep disruption than learning and memory.
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Affiliation(s)
- S. Tanner Roach
- Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL, United States
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Melanie C. Ford
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Vikram Simhambhatla
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Vasilios Loutrianakis
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Hamza Farah
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Zhaoyi Li
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Erica M. Periandri
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Dina Abdalla
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Irene Huang
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Arjan Kalra
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
| | - Paul J. Shaw
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, United States
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15
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Kendall-Bar JM, Williams TM, Mukherji R, Lozano DA, Pitman JK, Holser RR, Keates T, Beltran RS, Robinson PW, Crocker DE, Adachi T, Lyamin OI, Vyssotski AL, Costa DP. Brain activity of diving seals reveals short sleep cycles at depth. Science 2023; 380:260-265. [PMID: 37079694 DOI: 10.1126/science.adf0566] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Sleep is a crucial part of the daily activity patterns of mammals. However, in marine species that spend months or entire lifetimes at sea, the location, timing, and duration of sleep may be constrained. To understand how marine mammals satisfy their daily sleep requirements while at sea, we monitored electroencephalographic activity in wild northern elephant seals (Mirounga angustirostris) diving in Monterey Bay, California. Brain-wave patterns showed that seals took short (less than 20 minutes) naps while diving (maximum depth 377 meters; 104 sleeping dives). Linking these patterns to accelerometry and the time-depth profiles of 334 free-ranging seals (514,406 sleeping dives) revealed a North Pacific sleepscape in which seals averaged only 2 hours of sleep per day for 7 months, rivaling the record for the least sleep among all mammals, which is currently held by the African elephant (about 2 hours per day).
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Affiliation(s)
- Jessica M Kendall-Bar
- Scripps Institution of Oceanography, University of California San Diego, San Diego, CA, USA
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Terrie M Williams
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Ritika Mukherji
- Department of Neuroscience, University of Oxford, Oxford, UK
| | - Daniel A Lozano
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | | | - Rachel R Holser
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Theresa Keates
- Ocean Sciences Department, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Roxanne S Beltran
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Patrick W Robinson
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Daniel E Crocker
- Department of Biology, Sonoma State University, Rohnert Park, CA, USA
| | - Taiki Adachi
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Oleg I Lyamin
- Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA, USA
- A.N. Severtsov Institute of Ecology and Evolution, Moscow, Russia
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Daniel P Costa
- Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, USA
- Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, USA
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16
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Schiffmann C, Hellriegel L, Clauss M, Brother Stefan, Knibbs K, Wenker C, Hård T, Galeffi C. From left to right all through the night: Characteristics of lying rest in zoo elephants. Zoo Biol 2023; 42:17-25. [PMID: 35363895 PMCID: PMC10083898 DOI: 10.1002/zoo.21693] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/16/2022] [Accepted: 03/16/2022] [Indexed: 01/18/2023]
Abstract
Despite increased research during the past years, many characteristics of resting behavior in elephants are still unknown. For example, there is only limited data suggesting elephants express longer lying bouts and increased total nightly lying durations on soft substrates as compared to hard surfaces. Additionally, it has not been investigated how frequently elephants change body sides between lying bouts. Here we present these characteristics based on observations of nighttime lying behavior in 10 zoo elephants (5 African Loxodonta africana and 5 Asian Elephas maximus elephants) living in five different European facilities. We found that elephants housed on soft substrates have significantly increased total lying durations per night and longer average lying bouts. Furthermore, at 70%-85% of all bouts, a consistently higher frequency of side change between lying bouts occurred on soft substrates, leading to an overall equal laterality in resting behavior. Deviations from this pattern became evident in elephants living on nonsand flooring or/and in nondominant individuals of nonfamily groups, respectively. Based on our findings, we consider elephants to normally have several lying bouts per night with frequent side changes, given an appropriate substrate and healthy social environment. We encourage elephant-keeping facilities to monitor these characteristics in their elephants' nighttime behavior to determine opportunities for further improvements and detect alterations putatively indicating social or health problems in individual elephants at an early stage.
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Affiliation(s)
| | | | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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17
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Siegel JM. Sleep function: an evolutionary perspective. Lancet Neurol 2022; 21:937-946. [PMID: 36115365 PMCID: PMC9670796 DOI: 10.1016/s1474-4422(22)00210-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 01/05/2022] [Accepted: 05/05/2022] [Indexed: 12/25/2022]
Abstract
Prospective epidemiological studies in industrial societies indicate that 7 h of sleep per night in people aged 18 years or older is optimum, with higher and lower amounts of sleep predicting a shorter lifespan. Humans living a hunter-gatherer lifestyle (eg, tribal groups) sleep for 6-8 h per night, with the longest sleep durations in winter. The prevalence of insomnia in hunter-gatherer populations is low (around 2%) compared with the prevalence of insomnia in industrial societies (around 10-30%). Sleep deprivation studies, which are done to gain insights into sleep function, are often confounded by the effects of stress. Consideration of the duration of spontaneous daily sleep across species of mammals, which ranges from 2 h to 20 h, can provide important insights into sleep function without the stress of deprivation. Sleep duration is not related to brain size or cognitive ability. Rather, sleep duration across species is associated with their ecological niche and feeding requirements, indicating a role for wake-sleep balance in food acquisition and energy conservation. Brain temperature drops from waking levels during non-rapid eye movement (non-REM) sleep and rises during REM sleep. Average daily REM sleep time of homeotherm orders is negatively correlated with average body and brain temperature, with the largest amount of REM sleep in egg laying (monotreme) mammals, moderate amounts in pouched (marsupial) mammals, lower amounts in placental mammals, and the lowest amounts in birds. REM sleep might, therefore, have a key role in the regulation of temperature and metabolism of the brain during sleep and in the facilitation of alert awakening.
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Affiliation(s)
- Jerome M Siegel
- Department of Psychiatry and Brain Research Institute, University of California, Los Angeles, CA, USA; Department of Veterans Affairs, Greater Los Angeles Healthcare System, Los Angeles, CA, USA.
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18
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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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19
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Williams E, Clark N, Rendle-Worthington J, Yon L. Behaviour and Welfare Impacts of Releasing Elephants from Overnight Tethers: A Zimbabwean Case Study. Animals (Basel) 2022; 12:ani12151933. [PMID: 35953922 PMCID: PMC9367438 DOI: 10.3390/ani12151933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/01/2022] [Accepted: 07/28/2022] [Indexed: 11/25/2022] Open
Abstract
Within the southern African elephant tourism industry, chaining or tethering elephants is still a relatively routine practice, despite the known negative impacts. Cited reasons for chaining include fear of aggressive interactions between elephants when handlers are absent, or a general increase in expression of aggressive behaviours (both to other elephants and to their human handlers). In Zimbabwe, concerns expressed include the danger of elephants escaping and entering human-inhabited areas. Four male semi-captive elephants at a Zimbabwe tourist facility were taken off overnight (~12 h) tethers and were placed in small pens (‘bomas’), approximate sizes from 110 m2 to 310 m2), as part of a strategy to improve elephant welfare. Behavioural data were collected from overnight videos from December 2019 to March 2020, between 18:00 to 06:00, using focal, instantaneous sampling (5-min interval). Data were collected for three nights at three time periods: (i) Tethered; (ii) approximately four weeks post-release; (iii) approximately eight weeks post-release. Behavioural change over these time points was analysed using general linear models with quasibinomial error structures. Behavioural changes indicative of improved welfare were observed following these management changes, and no significant increases in aggression were observed either between elephants, or towards their human handlers. Proportion of time engaging in lying rest was higher in the first month after release from tethering (mean ± SD, 50 ± 14%) than when elephants were tethered (20 ± 18%) (p < 0.05). Additionally, although not statistically significant, stereotypies were reduced when elephants were no longer tethered (4 ± 6% observations tethered compared to 2 ± 2% off tethers), and positive social behaviour also increased (1 ± 1% on tethers, 2 ± 2% off tethers), with the greatest improvements seen in the pair-housed elephants. To improve elephant welfare in southern African tourism facilities we strongly advocate that less restrictive management practices which enable greater choice and freedom of movement overnight are implemented.
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Affiliation(s)
- Ellen Williams
- Department of Animal Health, Behaviour and Welfare, Harper Adams University, Newport TF10 8NB, UK;
| | - Natasha Clark
- School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington LE12 5RD, UK;
| | - Jake Rendle-Worthington
- eleCREW, Zimbabwe reg Trust, Jafuta Reserve, Victoria Falls 999135, Zimbabwe;
- We Are All Mammals, CIO Reg No. 1184219, Broomfield TA5 2EQ, UK
| | - Lisa Yon
- School of Veterinary Medicine and Science, The University of Nottingham, Sutton Bonington LE12 5RD, UK;
- Correspondence: ; Tel.: +44-(0)115-951-6358
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20
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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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21
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Rial RV, Canellas F, Akaârir M, Rubiño JA, Barceló P, Martín A, Gamundí A, Nicolau MC. The Birth of the Mammalian Sleep. BIOLOGY 2022; 11:biology11050734. [PMID: 35625462 PMCID: PMC9138988 DOI: 10.3390/biology11050734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/05/2022] [Indexed: 11/16/2022]
Abstract
Simple Summary Mammals evolved from reptiles as a consequence of an evolutionary bottleneck. Some diurnal reptiles extended their activity, first to twilight and then to the entire dark time. This forced the change of the visual system. Pursuing maximal sensitivity, they abandoned the filters protecting the eyes against the dangerous diurnal light, which, in turn, forced immobility in lightproof burrows during light time. This was the birth of the mammalian sleep. Then, the Cretacic-Paleogene extinction of dinosaurs leaved free the diurnal niche and allowed the expansion of a few early mammals to diurnal life and the high variability of sleep traits. On the other hand, we propose that the idling rest is a state showing homeostatic regulation. Therefore, the difference between behavioral rest and wakeful idling is rather low: both show quiescence, raised sensory thresholds, reversibility, specific sleeping-resting sites and body positions, it is a pleasing state, and both are dependent of circadian and homeostatic regulation. Indeed, the most important difference is the unconsciousness of sleep and the consciousness of wakeful idling. Thus, we propose that sleep is a mere upgrade of the wakeful rest, and both may have the same function: guaranteeing rest during a part of the daily cycle. Abstract Mammals evolved from small-sized reptiles that developed endothermic metabolism. This allowed filling the nocturnal niche. They traded-off visual acuity for sensitivity but became defenseless against the dangerous daylight. To avoid such danger, they rested with closed eyes in lightproof burrows during light-time. This was the birth of the mammalian sleep, the main finding of this report. Improved audition and olfaction counterweighed the visual impairments and facilitated the cortical development. This process is called “The Nocturnal Evolutionary Bottleneck”. Pre-mammals were nocturnal until the Cretacic-Paleogene extinction of dinosaurs. Some early mammals returned to diurnal activity, and this allowed the high variability in sleeping patterns observed today. The traits of Waking Idleness are almost identical to those of behavioral sleep, including homeostatic regulation. This is another important finding of this report. In summary, behavioral sleep seems to be an upgrade of Waking Idleness Indeed, the trait that never fails to show is quiescence. We conclude that the main function of sleep consists in guaranteeing it during a part of the daily cycle.
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Affiliation(s)
- Rubén V. Rial
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- Correspondence: ; Tel.: +34-971-173-147; Fax: +34-971-173-184
| | - Francesca Canellas
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Mourad Akaârir
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - José A. Rubiño
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Pere Barceló
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Aida Martín
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - Antoni Gamundí
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
| | - M. Cristina Nicolau
- Laboratori de Neurofisiologia del Son i dels Ritmes Biològics, Grup de Recerca Neurofisiologia del Son i Ritmes Biològics, Department of Biologia, Universitat de les Illes Balears, Ctra Valldemossa, km 7.5, 07122 Palma de Mallorca, Illes Balears, Spain; (F.C.); (M.A.); (J.A.R.); (P.B.); (A.M.); (A.G.); (M.C.N.)
- IdISBa, Institut d’Investigació Sanitària de les Illes Balears, Hospital Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
- IUNICS, Institut Universitari d’Investigació en Ciències de la Salut, Hospital Universitary Son Espases, 07120 Palma de Mallorca, Illes Balears, Spain
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22
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Loftus JC, Harel R, Núñez CL, Crofoot MC. Ecological and social pressures interfere with homeostatic sleep regulation in the wild. eLife 2022; 11:73695. [PMID: 35229719 PMCID: PMC8887896 DOI: 10.7554/elife.73695] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 01/18/2022] [Indexed: 12/12/2022] Open
Abstract
Sleep is fundamental to the health and fitness of all animals. The physiological importance of sleep is underscored by the central role of homeostasis in determining sleep investment – following periods of sleep deprivation, individuals experience longer and more intense sleep bouts. Yet, most sleep research has been conducted in highly controlled settings, removed from evolutionarily relevant contexts that may hinder the maintenance of sleep homeostasis. Using triaxial accelerometry and GPS to track the sleep patterns of a group of wild baboons (Papio anubis), we found that ecological and social pressures indeed interfere with homeostatic sleep regulation. Baboons sacrificed time spent sleeping when in less familiar locations and when sleeping in proximity to more group-mates, regardless of how long they had slept the prior night or how much they had physically exerted themselves the preceding day. Further, they did not appear to compensate for lost sleep via more intense sleep bouts. We found that the collective dynamics characteristic of social animal groups persist into the sleep period, as baboons exhibited synchronized patterns of waking throughout the night, particularly with nearby group-mates. Thus, for animals whose fitness depends critically on avoiding predation and developing social relationships, maintaining sleep homeostasis may be only secondary to remaining vigilant when sleeping in risky habitats and interacting with group-mates during the night. Our results highlight the importance of studying sleep in ecologically relevant contexts, where the adaptive function of sleep patterns directly reflects the complex trade-offs that have guided its evolution.
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Affiliation(s)
- J Carter Loftus
- Department of Anthropology, University of California, Davis, Davis, United States.,Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany.,Department of Biology, University of Konstanz, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.,Mpala Research Centre, Nanyuki, Kenya.,Animal Behavior Graduate Group, University of California, Davis, Davis, United States
| | - Roi Harel
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany.,Mpala Research Centre, Nanyuki, Kenya
| | - Chase L Núñez
- Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.,Mpala Research Centre, Nanyuki, Kenya
| | - Margaret C Crofoot
- Department of Anthropology, University of California, Davis, Davis, United States.,Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany.,Department of Biology, University of Konstanz, Konstanz, Germany.,Centre for the Advanced Study of Collective Behaviour, University of Konstanz, Konstanz, Germany.,Mpala Research Centre, Nanyuki, Kenya.,Animal Behavior Graduate Group, University of California, Davis, Davis, United States
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23
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Gübert J, Hahn‐Klimroth M, Dierkes PW. BOVIDS: A deep learning-based software package for pose estimation to evaluate nightly behavior and its application to common elands ( Tragelaphus oryx) in zoos. Ecol Evol 2022; 12:e8701. [PMID: 35342615 PMCID: PMC8928879 DOI: 10.1002/ece3.8701] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 12/29/2022] Open
Abstract
Only a few studies on the nocturnal behavior of African ungulates exist so far, with mostly small sample sizes. For a comprehensive understanding of nocturnal behavior, the data basis needs to be expanded. Results obtained by observing zoo animals can provide clues for the study of wild animals and furthermore contribute to a better understanding of animal welfare and better husbandry conditions in zoos. The current contribution reduces the lack of data in two ways. First, we present a stand-alone open-source software package based on deep learning techniques, named Behavioral Observations by Videos and Images using Deep-Learning Software (BOVIDS). It can be used to identify ungulates in their enclosure and to determine the three behavioral poses "Standing," "Lying-head up," and "Lying-head down" on 11,411 h of video material with an accuracy of 99.4%. Second, BOVIDS is used to conduct a case study on 25 common elands (Tragelaphus oryx) out of 5 EAZA zoos with a total of 822 nights, yielding the first detailed description of the nightly behavior of common elands. Our results indicate that age and sex are influencing factors on the nocturnal activity budget, the length of behavioral phases as well as the number of phases per behavioral state during the night while the keeping zoo has no significant influence. It is found that males spend more time in REM sleep posture than females while young animals spend more time in this position than adult ones. Finally, the results suggest a rhythm between the Standing and Lying phases among common elands that opens future research directions.
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Affiliation(s)
- Jennifer Gübert
- Faculty of Biological SciencesBioscience Education and Zoo BiologyGoethe UniversityFrankfurtGermany
| | | | - Paul W. Dierkes
- Faculty of Biological SciencesBioscience Education and Zoo BiologyGoethe UniversityFrankfurtGermany
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24
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Farsi H, Harti D, Rachid Achaâban M, Piro M, Ouassat M, Challet E, Pévet P, El Allali K. Seasonal variations in locomotor activity rhythm and diurnal activity in the dromedary camel (Camelus dromedarius) under mesic semi-natural conditions. Chronobiol Int 2021; 39:129-150. [PMID: 34965824 DOI: 10.1080/07420528.2021.1984936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The dromedary camel (Camelus dromedarius) is a large ungulate that copes well with the xeric environment of the desert. Its peculiar adaptation to heat and dehydration is well-known. However, its behavior and general activity is far from being completely understood. The present study was carried out to investigate the ecological effect of the various seasons on the locomotor activity (LA) rhythm and diurnal activity of this species. Six adult female camels were maintained under mesic semi-natural conditions of the environment during four periods of 10 days in each season: autumn, winter, spring and summer. In addition, three female camels were used to test the effect of rain on the LA rhythm during a period of 18 days during the winter. The animal's LA was recorded using the locomotion scoring method. Camels displayed a clear 24.0h LA rhythm throughout the four seasons. Activity was intense during Day-time (6-22 fold higher in comparison to night) and dropped or completely disappeared during nighttime. Mean daytime total activity was significantly higher in the summer as compared to winter. Regardless of the season, the active phase in camels coincided with the time of the photophase and thermophase. Furthermore, the daily duration of the time spent active was directly correlated to the seasonal changes of photoperiod. The diurnal activity remained unchanged over the four seasons. For each season, the start and the end of the active phase were synchronized with the onset of sunrise and sunset. At these time periods, temperature remained incredibly stable with a change ranging from 0.002 to 0.210°C; whereas, changes of light intensity were greater and faster with a change from 0.1 to 600 lux representing a variation of 3215-7192 fold in just 25-29 min. Rainfall affected the pattern of the LA rhythm with occurrence of abnormal nocturnal activity during nighttime disturbing nocturnal rest and sleep. Here we show that the dromedary camel exhibits significant seasonal changes of its activity within daylight hours. However, the diurnal pattern remains unchanged regardless of the season; whereas, abnormal nocturnal activity is observed during periods of rain. The activity onset and offset in this species seems to be primarily driven by the changes in light intensity at dusk and dawn.
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Affiliation(s)
- Hicham Farsi
- cComparative Anatomy Unit, Department of Biological and Pharmacological Veterinary Sciences, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Driss Harti
- cComparative Anatomy Unit, Department of Biological and Pharmacological Veterinary Sciences, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Mohamed Rachid Achaâban
- cComparative Anatomy Unit, Department of Biological and Pharmacological Veterinary Sciences, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Mohammed Piro
- Medicine and Surgical Unit of Domestic Animals, Department of Medicine, Surgery and Reproduction, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Mohammed Ouassat
- cComparative Anatomy Unit, Department of Biological and Pharmacological Veterinary Sciences, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
| | - Etienne Challet
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | | | - Khalid El Allali
- cComparative Anatomy Unit, Department of Biological and Pharmacological Veterinary Sciences, Hassan IInd Agronomy and Veterinary Medicine Institute, Rabat, Morocco
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25
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Zada D, Sela Y, Matosevich N, Monsonego A, Lerer-Goldshtein T, Nir Y, Appelbaum L. Parp1 promotes sleep, which enhances DNA repair in neurons. Mol Cell 2021; 81:4979-4993.e7. [PMID: 34798058 PMCID: PMC8688325 DOI: 10.1016/j.molcel.2021.10.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 10/19/2022]
Abstract
The characteristics of the sleep drivers and the mechanisms through which sleep relieves the cellular homeostatic pressure are unclear. In flies, zebrafish, mice, and humans, DNA damage levels increase during wakefulness and decrease during sleep. Here, we show that 6 h of consolidated sleep is sufficient to reduce DNA damage in the zebrafish dorsal pallium. Induction of DNA damage by neuronal activity and mutagens triggered sleep and DNA repair. The activity of the DNA damage response (DDR) proteins Rad52 and Ku80 increased during sleep, and chromosome dynamics enhanced Rad52 activity. The activity of the DDR initiator poly(ADP-ribose) polymerase 1 (Parp1) increased following sleep deprivation. In both larva zebrafish and adult mice, Parp1 promoted sleep. Inhibition of Parp1 activity reduced sleep-dependent chromosome dynamics and repair. These results demonstrate that DNA damage is a homeostatic driver for sleep, and Parp1 pathways can sense this cellular pressure and facilitate sleep and repair activity.
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Affiliation(s)
- David Zada
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yaniv Sela
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo 69978, Israel
| | - Noa Matosevich
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo 69978, Israel
| | - Adir Monsonego
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Tali Lerer-Goldshtein
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Yuval Nir
- Department of Physiology and Pharmacology, Sackler Faculty of Medicine, and Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo 69978, Israel
| | - Lior Appelbaum
- The Faculty of Life Sciences and the Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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26
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Žunkovič B, Schmidt M. Sleep: The great adaptive diversity. Curr Biol 2021; 31:R1527-R1530. [PMID: 34875243 DOI: 10.1016/j.cub.2021.10.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A new study shows that bird pupillary responses during sleep are opposite to those seen in mammals, findings that expand our understanding of the great adaptive diversity of sleep and the expression of its components across species.
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Affiliation(s)
- Breda Žunkovič
- Clinical Institute for Clinical Neurophysiology, University Medical Center Ljubljana, Ljubljana, Slovenia
| | - Markus Schmidt
- Department of Neurology, Center for Experimental Neurology, Bern University Hospital (Inselspital) and University, Bern, Switzerland; Ohio Sleep Medicine Institute, 4975 Bradenton Avenue, Dublin, OH 43017, USA.
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27
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Clauss M, Scriba M, Kioko J, Ganzhorn JU, Kiffner C. Camera-trap data do not indicate scaling of diel activity and cathemerality with body mass in an East African mammal assemblage. Ecol Evol 2021; 11:13846-13861. [PMID: 34707822 PMCID: PMC8525076 DOI: 10.1002/ece3.8090] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/19/2021] [Accepted: 08/24/2021] [Indexed: 11/11/2022] Open
Abstract
Diel activity patterns of animal species reflect constraints imposed by morphological, physiological, and behavioral trade-offs, but these trade-offs are rarely quantified for multispecies assemblages. Based on a systematic year-long camera-trap study in the species-rich mammal assemblage of Lake Manyara National Park (Tanzania), we estimated activity levels (hours active per day) and circadian rhythms of 17 herbivore and 11 faunivore species to determine the effects of body mass and trophic level on activity levels and cathemerality (the degree to which species are active throughout the day and night). Using generalized least squares and phylogenetic generalized least squares analyses, we found no support for the hypothesis that trophic level is positively associated with activity levels. We found no support for activity levels to scale positively with body mass in herbivores or to differ between ruminants and nonruminants; in faunivores, we also did not detect relationships between body mass and activity levels. Cathemerality was positively associated with activity levels but did not scale significantly with body mass. Overall, our findings caution against trophic level or body mass-associated generalized conclusions with regard to diel activity patterns.
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Affiliation(s)
- Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and WildlifeVetsuisse FacultyUniversity of ZurichZurichSwitzerland
| | - Miriam Scriba
- Animal Ecology and ConservationInstitute of ZoologyUniversität HamburgHamburgGermany
| | - John Kioko
- Center For Wildlife Management StudiesThe School For Field StudiesKaratuTanzania
| | - Jörg U. Ganzhorn
- Animal Ecology and ConservationInstitute of ZoologyUniversität HamburgHamburgGermany
| | - Christian Kiffner
- Center For Wildlife Management StudiesThe School For Field StudiesKaratuTanzania
- Junior Research Group Human‐Wildlife Conflict & CoexistenceLeibniz Centre for Agricultural Landscape Research (ZALF)MünchebergGermany
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28
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Abstract
Purpose of Review I review the current status of the hypothesis that sleep is critically involved in memory consolidation and conclude that there are major methodological problems with the studies used to support this hypothesis. Recent Findings Memory consolidation is similar in quiet waking and sleep (Humiston GB, Tucker MA, Summer T, Wamsley EJ. Sci Rep 18;9(1):19345, 2019), and suppression of REM sleep for long periods is compatible with learning and highly adaptive behavior (Lyamin OI, Korneva SM, Obukhova ED, Mukhametov LM, Siegel JM. Dokl Biol Sci 463:211-4, 2015; Lyamin OI, Kosenko PO, Korneva SM, Vyssotski AL, Mukhametov LM, Siegel JM. Current Biology 28(12):2000-5, 2018); despite their considerable abilities to navigate and remember, African elephants have very small amount of sleep, and learning interference effects have not been adequately controlled for in studies purporting to show sleep-dependent memory consolidation (Sosic-Vasic Z, Hille K, Kroner J, Spitzer M, Kornmeier J. Frontiers in psychology 9:82, 2018; Yonelinas AP, Ranganath C, Ekstrom AD, Wiltgen BJ. Nat Rev Neurosci 20(6):364-75, 2019). Summary Memory consolidation clearly occurs in both sleep and waking. Whether, and the extent to which, consolidation might differ in these two states has not been conclusively determined.
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29
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Lyamin OI, Siegel JM, Nazarenko EA, Rozhnov VV. Sleep in the lesser mouse-deer (Tragulus kanchil). Sleep 2021; 45:6346614. [PMID: 34370021 DOI: 10.1093/sleep/zsab199] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 07/05/2021] [Indexed: 11/13/2022] Open
Abstract
The mouse-deer or chevrotains are the smallest of the ungulates and ruminants. They are characterized by a number of traits which are considered plesiomorphic for the Artiodactyla order. The objective of this study was to examine sleep in the lesser mouse-deer (Tragulus kanchil), which is the smallest in this group (body mass <2.2 kg). Electroencephalogram, nuchal electromyogram, electrooculogram and body acceleration were recorded in 4 adult mouse-deer females using a telemetry system in Bu Gia Map National Park in Vietnam. The mouse-deer spent on average 49.7±3.0% of 24-h in NREM sleep. REM sleep occupied 1.7±0.3% of 24-h or 3.2±0.5% of total sleep time. The average duration of REM sleep episodes was 2.0±0.2 min, the average maximum was 5.1±1.1 min, and the longest episodes lasted 8 min. NREM sleep occurred in sternal recumbency with the head heals above the ground while 64.7+6.4% of REM sleep occurred with the head resting on the ground. The eyes were open throughout most of the NREM sleep period. The mouse-deer displayed polyphasic sleep and crepuscular peaks in activity (04:00-06:00 and 18:00-19:00). The largest amounts of NREM occurred in the morning (06:00-09:00) and the smallest before dusk (at 04:00-06:00). REM sleep occurred throughout most of the daylight hours (08:00-16:00) and in the first half of the night (19:00-02:00). We suggest that the pattern and timing of sleep in the lesser mouse-deer is adapted to the survival of a small herbivorous animal, subject to predation, living in high environmental temperatures in tropical forest undergrowth.
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Affiliation(s)
- Oleg I Lyamin
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia.,Joint Russian- Vietnamese Tropical Research and Technological Center, Hanoi, Vietnam.,Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Jerome M Siegel
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA, USA
| | - Evgeny A Nazarenko
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia.,Joint Russian- Vietnamese Tropical Research and Technological Center, Hanoi, Vietnam
| | - Viatcheslav V Rozhnov
- A.N. Severtsov Institute of Ecology and Evolution of the Russian Academy of Sciences, Moscow, Russia.,Joint Russian- Vietnamese Tropical Research and Technological Center, Hanoi, Vietnam
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30
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Eagleman DM, Vaughn DA. The Defensive Activation Theory: REM Sleep as a Mechanism to Prevent Takeover of the Visual Cortex. Front Neurosci 2021; 15:632853. [PMID: 34093109 PMCID: PMC8176926 DOI: 10.3389/fnins.2021.632853] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 04/27/2021] [Indexed: 11/13/2022] Open
Abstract
Regions of the brain maintain their territory with continuous activity: if activity slows or stops (e.g., because of blindness), the territory tends to be taken over by its neighbors. A surprise in recent years has been the speed of takeover, which is measurable within an hour. These findings lead us to a new hypothesis on the origin of REM sleep. We hypothesize that the circuitry underlying REM sleep serves to amplify the visual system's activity periodically throughout the night, allowing it to defend its territory against takeover from other senses. We find that measures of plasticity across 25 species of primates correlate positively with the proportion of rapid eye movement (REM) sleep. We further find that plasticity and REM sleep increase in lockstep with evolutionary recency to humans. Finally, our hypothesis is consistent with the decrease in REM sleep and parallel decrease in neuroplasticity with aging.
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Affiliation(s)
- David M. Eagleman
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Don A. Vaughn
- Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, United States
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31
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Lyamin OI, Kibalnikov AS, Siegel JM. Sleep in ostrich chicks (Struthio camelus). Sleep 2021; 44:6010143. [PMID: 33249508 DOI: 10.1093/sleep/zsaa259] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/03/2020] [Indexed: 11/12/2022] Open
Abstract
It has been reported that adult ostriches displayed the longest episodes of rapid eye movement (REM) sleep (up to 5 min) and more REM sleep (24% of the nighttime) than any other bird species. If the mammalian ontogenetic trend exists in the ostrich, then the amounts of REM and the duration of sleep episodes in young ostriches may be greater than those reported in adults. We investigated sleep in 1.5-3.5 month old ostrich chicks. Recordings were conducted during nighttime (20:00-08:00), the main sleep period in ostriches, which are diurnal. The polygrams were scored in 4-s epochs for waking, non-rapid eye movement (NREM) sleep and REM sleep, as in other bird studies. REM sleep in ostrich chicks occurred during both cortical EEG activation and during slow waves, as was described in adult ostriches. The chicks spent 69.3% ± 1.5% of the night in NREM sleep. REM sleep occupied 14.1% ± 1.8% of the night or 16.8% ± 2.0% of nighttime sleep. Episodes of REM sleep lasted on average 10 ± 1 s and ranged between 4 and 40 s. Therefore, the total amount and duration of REM sleep episodes in ostrich chicks were substantially smaller than reported in adult ostriches while the amounts of NREM sleep did not greatly differ. The developmental profile of REM sleep ontogenesis in the ostrich may be remarkably different from what has been reported in all studied mammals and birds.
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Affiliation(s)
- Oleg I Lyamin
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA.,Greater Los Angeles Healthcare System, North Hills, CA.,A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Moscow, Russia
| | | | - Jerome M Siegel
- Department of Psychiatry, University of California Los Angeles, Los Angeles, CA.,Greater Los Angeles Healthcare System, North Hills, CA
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32
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Insights into Activity of Zoo Housed Asian Elephants (Elephas maximus) during Periods of Limited Staff and Visitor Presence, a Focus on Resting Behaviour. JOURNAL OF ZOOLOGICAL AND BOTANICAL GARDENS 2021. [DOI: 10.3390/jzbg2010008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Historically, behaviour of zoo housed species during hours of limited staff and visitor presence has been poorly studied, largely due to the lack of appropriate technology. Advances in digital monitoring equipment and facility design by European elephant holders has given researchers scope to accurately evaluate behaviour for this species over 24 hrs. Various behavioural indicators of welfare have now been identified for zoo housed elephants; however the relationship between resting behaviour and welfare experience has been an area highlighted to require additional research. Lying rest is a potential positive welfare indicator for this species, with studies suggesting that engagement in lying rest can be used to monitor both psychological and physiological wellbeing. Throughout this work we aim to give insights into the behaviour of individual Asian elephants at ZSL Whipsnade Zoo, specifically between the hours of 16:00 and 10:00. In addition to presenting the activity budgets of our study individuals during these times, we explore individual engagement in resting behaviour. Furthermore, we evaluate the social associations of our study group during rest. We provide evidence that unrelated individuals can form strong associations with conspecifics when resting and show that life history is a factor to consider when evaluating social compatibility between group members. Finally, we demonstrate the positive role that calves and juvenile individuals can play in facilitating meaningful associations between group members during rest. Our study highlights the importance of evaluating behaviour during understudied time periods in order to obtain a holistic view of individual welfare, further emphasising the importance of adopting an evidence-based approach to management for this species in zoos.
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33
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Burger AL, Hartig J, Dierkes PW. Biological and environmental factors as sources of variation in nocturnal behavior of giraffe. Zoo Biol 2021; 40:171-181. [PMID: 33666286 DOI: 10.1002/zoo.21596] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/09/2021] [Indexed: 01/01/2023]
Abstract
Upon a drastic decline of the giraffe population in the wild, conservation efforts and therefore the role of zoos have become more important than ever. With their unique opportunities, zoos provide excellent conditions to study animal behavior, expanding the knowledge about the giraffe's behavior repertoire and their ability to adapt. This study therefore examined the nocturnal behavior of 63 giraffe living in 13 different EAZA zoos across Germany and the Netherlands. Giraffe were observed and videos recorded via infrared sensitive cameras during the winter seasons 2015-2018. The observation period spanned nightly from 17:00 to 7:00. Thus, 198 nights, with a total of 2772 h were recorded and analyzed. Linear mixed models were then used to assess potential biological and environmental factors influencing behavior during the dark phase. Results show that individual variables such as age, subspecies and motherhood determined nocturnal activity and sleep behavior most. Among the variables studied, husbandry conditions and environmental factors complying with EAZA standards had no influence on the giraffe's nocturnal behavior. By combining nocturnal activity analyses and an assessment of potential influencing factors, our findings present a holistic approach to a better understanding of captive giraffe behavior and allow for management implications.
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Affiliation(s)
- Anna Lena Burger
- Bioscience Education and Zoo Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Johannes Hartig
- Department of Educational Quality and Evaluation, DIPF, Leibniz Institute for Research and Information in Education, Frankfurt am Main, Germany
| | - Paul W Dierkes
- Bioscience Education and Zoo Biology, Goethe University Frankfurt, Frankfurt am Main, Germany
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Sleep in two free-roaming blue wildebeest ( Connochaetes taurinus), with observations on the agreement of polysomnographic and actigraphic techniques. IBRO Neurosci Rep 2021; 10:142-152. [PMID: 34179868 PMCID: PMC8211919 DOI: 10.1016/j.ibneur.2021.02.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 02/09/2021] [Indexed: 12/28/2022] Open
Abstract
Most studies examining sleep in mammals are done under controlled conditions in laboratory/zoological facilities with few studies being conducted in their natural environment. It is not always possible to record sleep polysomnographically (PSG) from animals in their natural environments, as PSG is invasive, requiring the surgical implantation of electrodes on the surface of the brain. In contrast, actigraphy (ACT) has been shown to be a minimally-invasive method to objectively measure overall sleep times in some mammals, although not revealing specific sleep states. The aim of this study is two-fold, first, to measure sleep polysomnographically in free-roaming blue wildebeest (Connochaetes taurinus) under the most natural conditions possible, and second, to establish the degree of concordance between ACT and PSG recordings undertaken simultaneously in the same individuals. Here we examined sleep in the blue wildebeest, in a naturalistic setting, using both polysomnography (PSG) and actigraphy (ACT). PSG showed that total sleep time (TST) in the blue wildebeest for a 24-h period was 4.53 h (±0.12 h), 4.26 h (±0.11 h) spent in slow wave (non-REM) sleep and 0.28 h (±0.01 h) spent in rapid eye movement (REM) sleep, with 19.47 h (±0.12 h) spent in Wake. ACT showed that the blue wildebeest spent 19.23 h (±0.18 h) Active and 4.77 h (±0.18 h) Inactive. For both animals studied, a fair agreement between the two techniques for sleep scoring was observed, with approximately 45% of corresponding epochs analyzed being scored as both sleep (using PSG) and inactive (using ACT).
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Manger PR, Siegel JM. Do all mammals dream? J Comp Neurol 2020; 528:3198-3204. [PMID: 31960424 PMCID: PMC8211436 DOI: 10.1002/cne.24860] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/16/2020] [Accepted: 01/16/2020] [Indexed: 12/26/2022]
Abstract
The presence of dreams in human sleep, especially in REM sleep, and the detection of physiologically similar states in mammals has led many to ponder whether animals experience similar sleep mentation. Recent advances in our understanding of the anatomical and physiological correlates of sleep stages, and thus dreaming, allow a better understanding of the possibility of dream mentation in nonhuman mammals. Here, we explore the potential for dream mentation, in both non-REM and REM sleep across mammals. If we take a hard-stance, that dream mentation only occurs during REM sleep, we conclude that it is unlikely that monotremes, cetaceans, and otariid seals while at sea, have the potential to experience dream mentation. Atypical REM sleep in other species, such as African elephants and Arabian oryx, may alter their potential to experience REM dream mentation. Alternatively, evidence that dream mentation occurs during both non-REM and REM sleep, indicates that all mammals have the potential to experience dream mentation. This non-REM dream mentation may be different in the species where non-REM is atypical, such as during unihemispheric sleep in aquatic mammals (cetaceans, sirens, and Otariid seals). In both scenarios, the cetaceans are the least likely mammalian group to experience vivid dream mentation due to the morphophysiological independence of their cerebral hemispheres. The application of techniques revealing dream mentation in humans to other mammals, specifically those that exhibit unusual sleep states, may lead to advances in our understanding of the neural underpinnings of dreams and conscious experiences.
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Affiliation(s)
- Paul R. Manger
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, Republic of South Africa
| | - Jerome M. Siegel
- Department of Psychiatry, School of Medicine, and Brain Research Institute, University of California, Los Angeles, California
- Brain Research Institute, Neurobiology Research, Sepulveda VA Medical Center, Los Angeles, California
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Connelly F, Johnsson RD, Aulsebrook AE, Mulder RA, Hall ML, Vyssotski AL, Lesku JA. Urban noise restricts, fragments, and lightens sleep in Australian magpies. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 267:115484. [PMID: 32882458 DOI: 10.1016/j.envpol.2020.115484] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 05/20/2023]
Abstract
Urban areas are inherently noisy, and this noise can disrupt biological processes as diverse as communication, migration, and reproduction. We investigated how exposure to urban noise affects sleep, a process critical to optimal biological functioning, in Australian magpies (Cracticus tibicen). Eight magpies experimentally exposed to noise in captivity for 24-h spent more time awake, and less time in non-rapid eye movement (non-REM) and REM sleep at night than under quiet conditions. Sleep was also fragmented, with more frequent interruptions by wakefulness, shorter sleep episode durations, and less intense non-REM sleep. REM sleep was particularly sensitive to urban noise. Following exposure to noise, magpies recovered lost sleep by engaging in more, and more intense, non-REM sleep. In contrast, REM sleep showed no rebound. This might indicate a long-term cost to REM sleep loss mediated by noise, or contest hypotheses regarding the functional value of this state. Overall, urban noise has extensive, disruptive impacts on sleep composition, architecture, and intensity in magpies. Future work should consider whether noise-induced sleep restriction and fragmentation have long-term consequences.
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Affiliation(s)
- Farley Connelly
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia; School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia.
| | - Robin D Johnsson
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Anne E Aulsebrook
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia; School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia
| | - Raoul A Mulder
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Michelle L Hall
- School of BioSciences, The University of Melbourne, Melbourne, Victoria, 3010, Australia; Bush Heritage Australia, Melbourne, Victoria, 3000, Australia; School of Biological Sciences, The University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Zurich, 8006, Switzerland
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne, Victoria, 3086, Australia; Research Centre for Future Landscapes, La Trobe University, Melbourne, Victoria, 3086, Australia
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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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Reinhardt KD. Wild primate sleep: understanding sleep in an ecological context. CURRENT OPINION IN PHYSIOLOGY 2020. [DOI: 10.1016/j.cophys.2020.04.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Dissel S. Drosophila as a Model to Study the Relationship Between Sleep, Plasticity, and Memory. Front Physiol 2020; 11:533. [PMID: 32547415 PMCID: PMC7270326 DOI: 10.3389/fphys.2020.00533] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 04/30/2020] [Indexed: 12/28/2022] Open
Abstract
Humans spend nearly a third of their life sleeping, yet, despite decades of research the function of sleep still remains a mystery. Sleep has been linked with various biological systems and functions, including metabolism, immunity, the cardiovascular system, and cognitive functions. Importantly, sleep appears to be present throughout the animal kingdom suggesting that it must provide an evolutionary advantage. Among the many possible functions of sleep, the relationship between sleep, and cognition has received a lot of support. We have all experienced the negative cognitive effects associated with a night of sleep deprivation. These can include increased emotional reactivity, poor judgment, deficit in attention, impairment in learning and memory, and obviously increase in daytime sleepiness. Furthermore, many neurological diseases like Alzheimer’s disease often have a sleep disorder component. In some cases, the sleep disorder can exacerbate the progression of the neurological disease. Thus, it is clear that sleep plays an important role for many brain functions. In particular, sleep has been shown to play a positive role in the consolidation of long-term memory while sleep deprivation negatively impacts learning and memory. Importantly, sleep is a behavior that is adapted to an individual’s need and influenced by many external and internal stimuli. In addition to being an adaptive behavior, sleep can also modulate plasticity in the brain at the level of synaptic connections between neurons and neuronal plasticity influences sleep. Understanding how sleep is modulated by internal and external stimuli and how sleep can modulate memory and plasticity is a key question in neuroscience. In order to address this question, several animal models have been developed. Among them, the fruit fly Drosophila melanogaster with its unparalleled genetics has proved to be extremely valuable. In addition to sleep, Drosophila has been shown to be an excellent model to study many complex behaviors, including learning, and memory. This review describes our current knowledge of the relationship between sleep, plasticity, and memory using the fly model.
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Affiliation(s)
- Stephane Dissel
- Department of Molecular Biology and Biochemistry, School of Biological and Chemical Sciences, University of Missouri-Kansas City, Kansas City, MO, United States
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Rossman ZT, Padfield C, Young D, Hart BL, Hart LA. Contagious Yawning in African Elephants (Loxodonta africana): Responses to Other Elephants and Familiar Humans. Front Vet Sci 2020; 7:252. [PMID: 32457923 PMCID: PMC7225334 DOI: 10.3389/fvets.2020.00252] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 04/16/2020] [Indexed: 11/13/2022] Open
Abstract
While spontaneous yawning is common across all vertebrate classes, contagious yawning is less common and has been observed only in a few species of social animals. Interspecific contagious yawning in response to yawning by humans has been observed only by chimpanzees and dogs. After confirming additional occurrences of intraspecific contagious yawning in a group of captive African elephants previously studied, we further investigated the potential for the same group of elephants to engage in interspecific contagious yawning with familiar human handlers. Ten captive African elephants, most of whom had been previously studied, were observed over 13 nights for evidence of intraspecific contagious yawning. Seven of these elephants were also involved in trials where familiar handlers performed staged yawns, as well as trials with staged non-yawning gapes, or trials with no yawns or gapes. Incorporating previously collected contagious yawning data, we describe nine instances of intraspecific contagious yawning in the elephants. Three of the seven elephants yawned contagiously in response to humans during the interspecific yawning trials. This is the first report of interspecific contagious yawning by elephants in response to yawns by familiar humans.
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Affiliation(s)
- Zoë T Rossman
- Department of Evolution and Ecology, University of California, Davis, Davis, CA, United States
| | - Clare Padfield
- African Elephant Research Unit Knysna Elephant Park, Western Cape, South Africa
| | - Debbie Young
- African Elephant Research Unit Knysna Elephant Park, Western Cape, South Africa
| | - Benjamin L Hart
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Lynette A Hart
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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Melnattur K, Zhang B, Shaw PJ. Disrupting flight increases sleep and identifies a novel sleep-promoting pathway in Drosophila. SCIENCE ADVANCES 2020; 6:eaaz2166. [PMID: 32494708 PMCID: PMC7209998 DOI: 10.1126/sciadv.aaz2166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/25/2020] [Indexed: 06/06/2023]
Abstract
Sleep is plastic and is influenced by ecological factors and environmental changes. The mechanisms underlying sleep plasticity are not well understood. We show that manipulations that impair flight in Drosophila increase sleep as a form of sleep plasticity. We disrupted flight by blocking the wing-expansion program, genetically disrupting flight, and by mechanical wing perturbations. We defined a new sleep regulatory circuit starting with specific wing sensory neurons, their target projection neurons in the ventral nerve cord, and the neurons they connect to in the central brain. In addition, we identified a critical neuropeptide (burs) and its receptor (rickets) that link wing expansion and sleep. Disrupting flight activates these sleep-promoting projection neurons, as indicated by increased cytosolic calcium levels, and stably increases the number of synapses in their axonal projections. These data reveal an unexpected role for flight in regulating sleep and provide new insight into how sensory processing controls sleep need.
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Affiliation(s)
- K. Melnattur
- Department of Neuroscience, Washington University School of Medicine, Campus Box 8108, 660 South Euclid Avenue, St. Louis, MO 63110, USA
| | - B. Zhang
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211, USA
| | - P. J. Shaw
- Department of Neuroscience, Washington University School of Medicine, Campus Box 8108, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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van Hasselt SJ, Rusche M, Vyssotski AL, Verhulst S, Rattenborg NC, Meerlo P. Sleep Time in the European Starling Is Strongly Affected by Night Length and Moon Phase. Curr Biol 2020; 30:1664-1671.e2. [PMID: 32197088 DOI: 10.1016/j.cub.2020.02.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/13/2020] [Accepted: 02/18/2020] [Indexed: 12/21/2022]
Abstract
Sleep is considered to be of crucial importance for performance and health, yet much of what we know about sleep is based on studies in a few mammalian model species under strictly controlled laboratory conditions. Data on sleep in different species under more natural conditions may yield new insights in the regulation and functions of sleep. We therefore performed a study with miniature electroencephalogram (EEG) data loggers in starlings under semi-natural conditions, group housed in a large outdoor enclosure with natural temperature and light. The birds showed a striking 5-h difference in the daily amount of non-rapid-eye-movement (NREM) sleep between winter and summer. This variation in the amount of NREM sleep was best explained by night length. Most sleep occurred during the night, but when summer nights became short, the animals displayed mid-day naps. The decay of NREM sleep spectral power in the slow-wave range (1.1-4.3 Hz) was steeper in the short nights than in the longer nights, which suggests that birds in summer have higher sleep pressure. Additionally, sleep was affected by moon phase, with 2 h of NREM sleep less during full moon. The starlings displayed very little rapid-eye-movement (REM) sleep, adding up to 1.3% of total sleep time. In conclusion, this study demonstrates a pronounced phenotypical flexibility in sleep in starlings under semi-natural conditions and shows that environmental factors have a major impact on the organization of sleep and wakefulness.
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Affiliation(s)
- Sjoerd J van Hasselt
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands
| | - Maria Rusche
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands; Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands.
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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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45
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Siegel JM. Sleep under evolutionarily relevant conditions. Sleep Med 2020; 67:244-245. [PMID: 32035745 DOI: 10.1016/j.sleep.2020.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Jerome M Siegel
- Semel Institute and Brain Research Institute, University of California, Los Angeles, CA, 90095, USA; VA Greater Los Angeles Healthcare System, 16111 Plummer St, Los Angeles 91343, USA.
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Kelly M, Collin S, Hemmi J, Lesku J. Evidence for Sleep in Sharks and Rays: Behavioural, Physiological, and Evolutionary Considerations. BRAIN, BEHAVIOR AND EVOLUTION 2019; 94:37-50. [DOI: 10.1159/000504123] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 10/14/2019] [Indexed: 11/19/2022]
Abstract
Sleep is widespread across the animal kingdom. However, most comparative sleep data exist for terrestrial vertebrates, with much less known about sleep in amphibians, bony fishes, and invertebrates. There is an absence of knowledge on sleep in cartilaginous fishes. Sharks and rays are amongst the earliest vertebrates, and may hold clues to the evolutionary history of sleep and sleep states found in more derived animals, such as mammals and birds. Here, we review the literature concerning activity patterns, sleep behaviour, and electrophysiological evidence for sleep in cartilaginous (and bony) fishes following an exhaustive literature search that found more than 80 relevant studies in laboratory and field environments. Evidence for sleep in sharks and rays that respire without swimming is preliminary; evidence for sleep in continuously swimming fishes is currently absent. We discuss ways in which the latter group might sleep concurrent with sustained movement, and conclude with suggestions for future studies in order to provide more comprehensive data on when, how, and why sharks and rays sleep.
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Schiffmann C, Hård T, Hjelm M, Clauss M. Soft and persistent-The influence of sand-flooring and calves on the resting behavior of a zoo-kept African elephant (Loxodonta africana) group. Zoo Biol 2019; 39:56-62. [PMID: 31663179 DOI: 10.1002/zoo.21521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 09/08/2019] [Accepted: 10/15/2019] [Indexed: 11/07/2022]
Abstract
Caring for all aspects of zoo elephants' well-being is considered a major challenge. Providing an appropriate flooring substrate to facilitate lying rest presents a meaningful part of a holistic management concept. Investigating the impact of a new sand flooring on the nocturnal resting behavior of a breeding group of seven African elephants living at one zoo revealed more total lying rest, longer bouts of lying rest and a reduced side preference in the adult females. With an average total daily lying rest of about 1.5-2.0 hrs, the investigated zoo elephants expressed longer lying rest compared to recently reported data from free-ranging individuals in Botswana. In addition, the presence of nursing calves in the observed elephant group seemed to impact the resting pattern of all group members, with around 60% of all lying bouts being discontinued after interruption by the youngsters. With respect to observed nursing during leaning rest, we encourage the installation of appropriate horizontal structures in breeding facilities to support leaning rest behavior of their female elephants. In doing so, zoos may improve rest quality of nursing females, and, in general, the welfare aspect of sleep for their elephants.
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Affiliation(s)
- Christian Schiffmann
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Switzerland
| | | | | | - Marcus Clauss
- Clinic for Zoo Animals, Exotic Pets and Wildlife, Vetsuisse Faculty, University of Zurich, Switzerland
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48
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Malungo IB, Gravett N, Bhagwandin A, Davimes JG, Manger PR. A Preliminary Description of the Sleep-Related Neural Systems in the Brain of the Blue Wildebeest, Connochaetes taurinus. Anat Rec (Hoboken) 2019; 303:1977-1997. [PMID: 31513360 DOI: 10.1002/ar.24265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Revised: 06/12/2019] [Accepted: 07/16/2019] [Indexed: 12/18/2022]
Abstract
The current study provides a detailed qualitative description of the organization of the cholinergic, catecholaminergic, serotonergic, orexinergic, and GABAergic sleep-related systems in the brain of the blue wildebeest (Connocheates taurinus), along with a quantitative analysis of the pontine cholinergic and noradrenergic neurons, and the hypothalamic orexinergic neurons. The aim of this study was to compare the nuclear organization of these systems to other mammalian species and specifically that reported for other Cetartiodactyla. In the brain of the blue wildebeest, from the basal forebrain to the pons, the nuclear organization of the cholinergic, catecholaminergic, serotonergic, and orexinergic systems, for the most part, showed a corresponding nuclear organization to that reported in other mammals and more specifically the Cetartiodactyla. Furthermore, the description and distribution of the GABAergic system, which was examined through immunostaining for the calcium binding proteins calbindin, calretinin, and parvalbumin, was also similar to that seen in other mammals. These findings indicate that sleep in the blue wildebeest is likely to show typically mammalian features in terms of the global brain activity of the generally recognized sleep states of mammals, but Cetartiodactyl-specific features of the orexinergic system may act to lower overall daily total sleep time in relation to similar sized non-Cetartiodactyl mammals. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1977-1997, 2020. © 2019 American Association for Anatomy.
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Affiliation(s)
- Illke B Malungo
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Nadine Gravett
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Adhil Bhagwandin
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Joshua G Davimes
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Paul R Manger
- School of Anatomical Sciences, Faulty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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49
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Reinhardt KD, Vyazovskiy VV, Hernandez-Aguilar RA, Imron MA, Nekaris KAI. Environment shapes sleep patterns in a wild nocturnal primate. Sci Rep 2019; 9:9939. [PMID: 31289296 PMCID: PMC6616475 DOI: 10.1038/s41598-019-45852-2] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/12/2019] [Indexed: 11/09/2022] Open
Abstract
Among primates, the suborder Haplorhini is considered to have evolved a consolidated monophasic sleep pattern, with diurnal species requiring a shorter sleep duration than nocturnal species. Only a few primate species have been systematically studied in their natural habitat where environmental variables, including temperature and light, have a major influence on sleep and activity patterns. Here we report the first sleep study on a nocturnal primate performed in the wild. We fitted seven wild Javan slow lorises (Nycticebus javanicus) in West Java, Indonesia with accelerometers that collected activity data, and installed climate loggers in each individual’s home range to collect ambient temperature readings (over 321 days in total). All individuals showed a strictly nocturnal pattern of activity and displayed a striking synchronisation of onset and cessation of activity in relation to sunset and sunrise. The longest consolidated rest episodes were typically clustered near the beginning and towards the end of the light period, and this pattern was inversely related to daily fluctuations of the ambient temperature. The striking relationship between daily activity patterns, light levels and temperature suggests a major role of the environment in shaping the daily architecture of waking and sleep. We concluded that well-known phenotypic variability in daily sleep amount and architecture across species may represent an adaptation to changes in the environment. Our data suggest that the consolidated monophasic sleep patterns shaped by environmental pressures observed in slow lorises represent phylogenetic inertia in the evolution of sleep patterns in humans.
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Affiliation(s)
- Kathleen D Reinhardt
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, United Kingdom. .,Center for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway.
| | - Vladyslav V Vyazovskiy
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
| | - R Adriana Hernandez-Aguilar
- Center for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway.,Department of Social Psychologyand Quantitative Psychology, Faculty of Psychology, University of Barcelona, Barcelona, Spain
| | - Muhammad Ali Imron
- Department of Forest Resources Conservation, Faculty of Forestry, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - K Anne-Isola Nekaris
- Nocturnal Primate Research Group, Oxford Brookes University, Oxford, United Kingdom
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Abstract
What is the 'simplest' animal that sleeps? When did sleep first evolve? Do all animals sleep? Tantalizing hints to answers come from new research showing that jellyfish, one of the earliest evolving groups of animals, have a sleep-like restful state.
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Affiliation(s)
- John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia.
| | - Linh M T Ly
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
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