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Sleep duration and placement within the twenty-four hour day have been primary indices utilized in the examination of sleep function. It is of value, therefore, to evaluate these variables in a wide range of animal species. The present paper examines the literature concerning sleep duration in over 150 animal species, including invertebrates, fish, amphibians, reptiles, birds, and 14 orders of mammals. We first present annotations of almost 200 studies, including number of animals used, photoperiod employed, sleep duration per twenty-four hours and placement of sleep period within the nychthemeron. Both behavioral and electrographic studies are reviewed, as are laboratory and field studies. These data are subsequently presented in a table with representative literature citations for each species. Following the table, a brief discussion is presented concerning some methodological issues which may affect the measurement of sleep duration and some suggestions are made for future examination of sleep duration.
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... The daily distribution and amount of sleep and wakefulness are determined by two principal and interacting systems: an endogenous circadian component that synchronizes sleep and awake periods to the environment using cues such as light, temperature, food availability, or social activities, and a homeostatic component that regulates the need and intensity of sleep according to the sleep-wake history, that is, the time previously spent asleep or awake (Borbely, 1982). Diurnal animals such as humans, apes, and dogs are mostly active during the day (light photoperiod) and sleep at night (dark photoperiod), while nocturnal animals such as rats and mice sleep the most during the light photoperiod (S. S. Campbell & Tobler, 1984). In terms of sleep patterns, humans and apes exhibit a monophasic sleep consisting of a single "consolidated" sleep block per 24-hour cycle. ...
... These two sleep states have been observed in all terrestrial mammals and birds studies so far (S. S. Campbell & Tobler, 1984;I. Tobler, 1995). ...
Article
With the advent of modern lifestyles, there has been a significant extension of daily activities, mostly at the cost of sleep. Lack of sleep affects many biological systems, including various cognitive functions, the immune system, metabolism, and pain. Both sleep and pain are complex neurological processes that encompass many dynamic components. As a result, defining the precise interactions between these two systems represents a challenge, especially for chronic paradigms. This chapter describes how sleep is measured and how it can be experimentally altered in humans and animal models, and, in turn, how sleep disturbances, either acute or chronic, can affect different aspects of pain. Possible mechanisms involved are discussed, including an increase in inflammatory processes, a loss of nociceptive inhibitory pathways, and a defect in the cognitive processing of noxious inputs.
... Behavioural quiescence has been observed across species, including invertebrates, and despite anatomical differences in the brain, some recent studies have indicated some correlates of REM and non-REM sleep even in D. melanogaster (Tainton-Heap et al 2021). Quiescence can be identified as sleep using four critical behavioural characteristics (Campbell and Tobler 1984). (a) A typical posture with reduced muscular activity that is compatible with sleep; (b) reversibility, i.e., sleep is reversible, and animals can be woken from their sleep, and this feature differentiates sleep from coma or paralysis. ...
... One of the important features of sleep is homeostatic control (Campbell and Tobler 1984). Organisms subjected to sleep deprivation experience sleep rebound after sleep loss. ...
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Sleep is conserved in the animal kingdom and plays a pivotal role in the adaptation of species. Sleep in Drosophila melanogaster is defined as any continuous 5 min of quiescence, shows a prominent siesta, and consolidated nighttime sleep. Here, we analyzed the sleep of two other species D. malerkotliana (DMK) and D. ananassae (DA), and compared it with D. melanogaster (DM). The DMK males and females have siesta like DM. However, unlike DM, flies continue to sleep beyond siesta till the evening. DA has a less prominent siesta compared to DM and DMK. In the morning, DA took a longer time to respond to the lights ON and continued to sleep for at least half an hour. The nighttime sleep of the DA flies is higher than the other two species. Average length of sleep episode is three times more than that of DM and DMK with few wake episodes. Thus, the nighttime sleep of DA males and females is deep and needs exposure to more potent stimuli to wake up relative to the other two species. DA males and females show higher sleep rebound than the other two species, suggesting the robustness of sleep homeostasis. Although total sleep of DMK and DA is similar, DA is a day-active species with highly consolidated night sleep. DMK, like DM, is a crepuscular species with a midday siesta. Thus, our results suggest that temporal partitioning of sleep, in sympatric species may contribute to temporal segregation.
... On the other hand, the difference (12D−12L) between the total activity during the 12-hour dark cycle (12D) and the total activity during the 12-hour light cycle (12L) showed a negative correlation with the MDA concentration in the hippocampal and cerebellar tissues. The ICR mice used in this study are nocturnal like other mice, so when the circadian rhythm is stabilized, they move actively during the dark cycle and sleep during the light cycle [26,42]. Given these characteristics, the 12D−12L level can be a stabilizing indicator of the sleep-wake circadian rhythm. ...
Article
Objective: This study aimed to explore the relationship among several indices of circadian rhythms and lipid peroxidation of brain tissue in mice. Methods: After entrainment of 4-week-old mice, one group was disrupted their circadian rhythms for three days and the other group for seven days (n = 10, respectively). After a recovery period, the Y-maze test, the elevated plus maze test, the tail suspension test, and the forced swimming test were conducted. To assess lipid peroxidation in brain tissue, thiobarbituric acid reactive substances were measured in the cortex, hippocampus, and cerebellum. Results: When circadian rhythms were disrupted and adapted back to their original rhythm, the recovery time of the 7-day disruption group (median 3.35 days) was significiantly faster than one of the 3-day disruption group (median 4.87 days). In the group with a 7-day disruption, mice that had recovered their rhythms early had higher malondialdehyde levels in their hippocampus compared to those with delayed recovery. The entrainment of circadian rhythms was negatively correlated with the malondialdehyde level of brain tissue. The behavioral test results showed no differences depending on the disruption durations or recovery patterns of circadian rhythms. Conclusion: These results suggest that disruption types, recovery patterns, and the entrainment of circadian rhythms are likely to affect oxidative stress in adolescents or young adult mice. Future study is needed to confirm and specify these results on the effects of circadian rhythms on oxidative stress and age-dependent effects.
... S leep is a fundamental behavior across the animal kingdom and is essential to normal animal function and survival 1,2 . This conserved behavior rely on the patterned activation of neuronal circuits throughout the brain. ...
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During sleep our brain switches between two starkly different brain states - slow wave sleep (SWS) and rapid eye movement (REM) sleep. While this two-state sleep pattern is abundant across birds and mammals, its existence in other vertebrates is not universally accepted, its evolutionary emergence is unclear and it is undetermined whether it is a fundamental property of vertebrate brains or an adaptation specific to homeotherms. To address these questions, we conducted electrophysiological recordings in the Agamid lizard, Laudakia vulgaris during sleep. We found clear signatures of two-state sleep that resemble the mammalian and avian sleep patterns. These states switched periodically throughout the night with a cycle of ~90 seconds and were remarkably similar to the states previously reported in Pogona vitticeps. Interestingly, in contrast to the high temperature sensitivity of mammalian states, state switches were robust to large variations in temperature. We also found that breathing rate, micro-movements and eye movements were locked to the REM state as they are in mammals. Collectively, these findings suggest that two-state sleep is abundant across the agamid family, shares physiological similarity to mammalian sleep, and can be maintain in poikilothems, increasing the probability that it existed in the cold-blooded ancestor of amniotes. Analysis of sleep states in the rough-tail rock agama lizard suggests neurophysiological similarity between reptilian and mammalian two-state sleep features. In contrast to mammals, these features remain robust to the large temperature fluctuations experienced by reptiles.
... Toutain et al. [30] specified a set of times spent by sheep in various states (awake, drowsy, slow-wave, paradoxical) that sum up to 554 min in an inactive state within a 15 h interval for old thin animals and 606 min for old fat animals. On the other hand, Campbell et al. described the total sleep time for sheep as averaging 3.8 h (16%) per 24 h, 87% of which occurring at night [31]. Anyhow, considering eight rest cycles per night, the period of inactivity would be in line with the times reported in the literature. ...
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Animal activity during the night period is of enormous importance since it represents approximately half of animals' lives, and monitoring it during this period makes it possible to detect problems related to well-being and safety, and allows us to infer energy expenditure on the basis of their activity level. The present study analyzes a sheep activity dataset created during the night period to validate non-invasive techniques of monitoring that can be used to infer energy expenditure at night and to detect abnormal nocturnal activity. The study allowed us to see cyclic changes in activity during the night period, composed of inactive and active periods, and identify sheep lying positions. The analysis of the joint activity of the flock allowed us to perceive a time lag in the rest cycles, which consisted of periods of activity of ewes undone between elements of the flock. Although it does not allow us to identify the components of the period of inactivity, since the method used does not monitor brain activity, the results allow us to confirm the cyclical character of the nocturnal activity of sheep that have been reported in the literature, as well as their typical posture when lying down. Although this is an exploratory application with a very small number of animals, the similarity between the results obtained and the results documented in the existing literature, which have mainly been obtained using invasive methods, is encouraging and suggests it is possible to rely on activity monitoring processes based on inertial sensors.
... In addition, future studies could investigate how couples decide whether to allow a dog into their bed or bedroom and how this decision impacts the interhuman relationship. Human-animal co-sleeping arrangements with cats are also worth pursuing, particularly since cats tend to be more active during the night than dogs (Campbell & Tobler, 1984). ...
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Human-animal co-sleeping is relatively common among dog owners; however, the nature of this practice is not well understood. Recent investigations have focused on the impact of human-dog co-sleeping on human sleep but have largely ignored the contextual nature of the practice, including with whom, why, and how people share their beds and bedrooms with their dogs. We explored the nature of human-dog co-sleeping among a large population of Australian dog owners ( n = 1136). Nearly half (49%) of participants reported sleeping with their dog in their bed, 20% indicated their dog slept in their bedroom but not in their bed, and 31% reported their dog slept outside their bedroom. The likelihood of bedsharing with one’s dog increased with participant age and bed size and was higher for individuals with small dogs than those with larger dogs. In addition, bedsharing with one’s dog was more common among individuals who did not have a human bed partner. For each unit increase in the MDORS Dog-Owner Interaction scale, the odds of sleeping with one’s dog increased by 1.39, and for each unit increase in the MDORS Emotional Closeness sub-scale, the odds increased by 1.08. For each unit increase in the MCPQ-R Motivation sub-scale, the odds of sleeping with one’s dog increased by 1.21.We found no association between whether the dog slept on the bed and self-reported sleep quality. However, participants whose dog slept somewhere other than their owner’s bed were 1.45 times more likely to report frequently waking up tired. Bedsharing appears unlikely to impact sleep quality negatively in any meaningful way. In fact, in many cases, dog(s) in the bed may facilitate a more restful night’s sleep than when they sleep elsewhere.
... The constant presence of family members at home during the lockdown might have made it difficult for cats to find a quiet space and time for their daily napping. In general, adult cats spend an average of 13-18 h a day sleeping, divided into multiple naps during the day, which is very important for their welfare [62,63]. This might also explain the presence of a very small number of cats (0.1%) hiding all the time during the lockdown in China. ...
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Considering the effects that the COVID-19 pandemic had and still has on human psychological health, it is expected that it might also affect household dogs’ and cats’ welfare. The current study explores the behavioral changes in dogs and cats before (BL) and during the lockdown (DL), as reported by their owners in China. Besides demographic parameters, variables related to the daily management of dogs and cats were analyzed in relation to behavioral problems, stress-related behaviors, and anxiety-related behaviors before and during the lockdown. A total of 261 questionnaires were collected. In general, behavioral problems and stress-related behaviors in dogs (p < 0.001) and cats (p < 0.001) decreased DL compared to BL, while anxiety-related behaviors in cats did not show any differences between the two periods considered. On the other hand, anxiety-related behaviors were more frequent in dogs DL (36.3%) compared to BL (35%), which were associated with reduced frequency of play activities with the owners (p = 0.016) and altered sleeping habits (p < 0.01). During the lockdown, dogs’ and cats’ daily routines and management (feeding and sleeping habits, dogs’ walks, dogs’ and cats’ play activities, litter box management, and cats’ lifestyle) experienced changes, but they were not associated with any behavioral issues. On the other hand, the behavioral issues considered for dogs and cats were more frequent BL, which were influenced by the daily management of the pets. The current study showed how critical the attention the owners can provide to the pets could be, to improve their companion animals’ welfare. Therefore, it is important to provide pet owners with behavioral management support both during particularly difficult periods such as a lockdown and during regular daily routines.
... Diet has been shown to be one such exogenous factor [23,39]. Depending on the type of food, different sleep patterns can be identified: carnivores show the highest, omnivores a lower and herbivores the lowest sleep duration over 24 hours [36,40]. In the field, hunting opportunities and the presence of competitors can influence predator activity [21,22]. ...
Article
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Mammals are constantly exposed to exogenous and endogenous influences that affect their behaviour and daily activity. Light and temperature, as well as anthropogenic factors such as husbandry routines, visitors, and feeding schedules are potential influences on animals in zoological gardens. In order to investigate the effects of some of these factors on animal behaviour, observational studies based on the analyses of activity budgets can be used. In this study, the daily and nightly activity budgets of six lions (Panthera leo) and five cheetahs (Acinonyx jubatus) from four EAZA institutions were investigated. Focused on the influencing factor light and feeding, we analysed these activity budgets descriptively. Behaviour was recorded and analysed during the winter months over an observation period of 14 days and 14 nights using infrared-sensitive cameras. Our results show that lions and cheetahs exhibit activity peaks at crepuscular and feeding times, regardless of husbandry. Thus, lions in captivity shift nocturnal behaviour familiar from the wild to crepuscular and diurnal times. In cheetahs, in contrast, captive and wild individuals show similar 24hr behavioural rhythms. The resting behaviour of both species is more pronounced at night, with cheetahs having a shorter overall sleep duration than lions. This study describes the results of the examined animals and is not predictive. Nevertheless, the results of this study make an important contribution to gaining knowledge about possible factors influencing the behaviour of lions and cheetahs in zoos and offer implications that could be useful for improving husbandry and management.
Chapter
Moonlight is the strongest naturally and predictably occurring nocturnal light source. Thus, many species have adapted to use moonlight as a reliable timing cue, either by directly reacting to moonlight or by entraining inner oscillators, like the monthly circalunar clock.Natural moonlight is characterized by intensity, spectrum, and complex timing, which regularly changes every night and across additional timescales. In order to understand the molecular and cellular machineries underlying moon-controlled physiology and behavior, lab experiments with organisms exhibiting well-documented lunar cycles are important. Tools such as TALEN- or Cas9/Crispr-engineered mutants or transgenesis are crucial to move from correlative studies to causal relationships. However, lab experiments face the problem that commonly used artificial light sources differ greatly from sun- and moonlight.To start to overcome this limitation, we have developed naturalistic sun- and moonlight sources, which closely mimic the natural light environment.We highlight the use of these naturalistic sun- and moonlight sources using the marine bristle worm Platynereis dumerilii, which controls its timing of reproduction with a circalunar clock. Importantly, while designed for Platynereis research, these methods can also be relatively easily adapted and used to study the effects of moonlight and/or monthly oscillator systems of other species. Finally, we provide an overview on statistical analyses of circalunar data sets.Key wordsMoonSunLightSpectraMarineUnderwaterCircalunarLunarCircalunidianMonthly clocksInner calendarLight engineeringTimingReproductionCircular statistics Platynereis dumerilii
Chapter
Sleep is a fundamental behavioral state that is observed throughout the animal kingdom, yet our understanding of this state remains limited. Zebrafish are a useful vertebrate animal model to dissect genetic and neuronal mechanisms underlying the regulation of sleep and wake states. The diurnal circadian pattern of sleep–wake cycles in zebrafish is similar to that of humans, and many sleep-regulating neuropeptides and hormones that are found in humans, such as melatonin and hypocretin, play similar roles in zebrafish. Due to their small size, rapid development, and optical transparency, larval zebrafish are well suited for high-throughput screens to identify genes, neurons, and drugs that regulate sleep. Numerous techniques and genetic tools have been established that enable powerful approaches to explore mechanisms that underlie zebrafish sleep. In this chapter, we will discuss current approaches to studying sleep in larval zebrafish, including detailed experimental procedures, and describe the advantages and limitations of each approach.Key wordsZebrafishSleepLocomotor activityBehaviorArousalCircadian rhythmGenetics
Article
Recovery sleep was studied for 3-5 days following 24 h of sleep deprivation (TSD) in normal rats and in rats lacking circadian rhythms (CRs) of sleep because of prior lesioning of the suprachiasmatic nuclei (SCN). One group of lesioned rats was run in constant dim light. Another lesioned group and an intact group were run on a 12:12 dark-light schedule with TSD and recovery beginning at lights-off. All groups showed immediate rebounds of high-amplitude NREM sleep and paradoxical sleep, confined mostly to the first 12-18 h of recovery, and decreases in moderate and low-amplitude NREM sleep during the first 6-12 h of recovery. Thus, sleep stage rebound priorities were little affected by CRs. Total sleep rebound was initially greatest in intact rats, but limited mostly to the first 12 h of recovery. Total sleep rebound was distributed over a longer period in SCN rats, but total accumulated rebound was similar in all groups. Thus, CRs appear to modulate the timing but not the amount of accumulated total sleep rebound. Results were interpreted in terms of ceiling effects on total sleep, delayed rebounds, and competition between CRs and homeostatic recovery processes. Recovery sleep of lesioned rats on the dark-light schedule was marked by a transient diurnal rhythm.
Chapter
The use of an analysis of the sleep-waking pattern and related behaviors as an indication of adaptation to different housing conditions is presently being investigated in German Landrace pigs. Sleep and wakefulness is determined by means of electroencephalography, and simultaneous behavioral observations are conducted by means of video equipment. The pigs are kept, first, in an open pen with straw, later in a farrowing crate with slatted floor. Preliminary results indicate that, although rooting behavior was greatly reduced after the change in housing system, with a corresponding increase in the time spent lying down inactively, no uniform change occurred in sleep and wakefulness. The possibility that earlier experience with slatted floor types without straw is responsible for the lack of change in sleeping behavior will be investigated in future experiments.