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Full-Text Articles in Life Sciences

A Bird’S-Eye View On The Function Of Sleep, Charles Amlaner, Niels Rattenborg Dec 2009

A Bird’S-Eye View On The Function Of Sleep, Charles Amlaner, Niels Rattenborg

Charles J. Amlaner

Sleep has been detected in every animal that has been adequately studied (Cirelli & Tononi, 2008). The ubiquitous nature of sleep suggests that it evolved early in the course of evolution and therefore may serve a conserved function essential to all animals. This hypothesis forms the rationale behind the development of “simple” animal models of sleep (Allada & Siegel, 2008; Mignot, 2008). By studying sleep in animals such as the fruit fly (Drosophila melanogaster), where the power of genetic techniques can be readily employed,we may gain insight into the initial (perhaps cellular) function of sleep, a function that may still be relevant to understanding sleep in humans. Indeed, recent studies have already demonstrated remarkable similarities between sleep in Drosophila and sleep in mammals (Hendricks, Finn, Panckeri, et al., 2000; Shaw, Cirelli, Greenspan, et al., 2000; reviewed in Cirelli & Bushey, 2008). Although the utility of studying sleep in“simple”animal models is undeniable, it is unlikely that this approach alone will tell the whole story, especially given that Drosophilado not exhibit brain states comparable to mammalian slow-wave sleep (SWS) and rapid eye-movement (REM) sleep (Cirelli, 2006; Cirelli & Bushey, 2008; Hendricks & Sehgal, 2004; Nitz, van Swinderen, Tononi, et al ...


Basics Of Sleep Guide, Charles Amlaner, Patrick Fuller Apr 2009

Basics Of Sleep Guide, Charles Amlaner, Patrick Fuller

Charles J. Amlaner

No abstract provided.


The Evolution Of Sleep, Charles Amlaner, John Lesku, Niels Rattenborg Dec 2008

The Evolution Of Sleep, Charles Amlaner, John Lesku, Niels Rattenborg

Charles J. Amlaner

No abstract provided.


Predator-Induced Plasticity In Sleep Architecture In Wild-Caught Norway Rats (Rattus Norvegicus), John Lesku, Rebekah Bark, Dolores Martinez-Gonzalez, Niels Rattenborg, Charles Amlaner, Steven Lima Jun 2008

Predator-Induced Plasticity In Sleep Architecture In Wild-Caught Norway Rats (Rattus Norvegicus), John Lesku, Rebekah Bark, Dolores Martinez-Gonzalez, Niels Rattenborg, Charles Amlaner, Steven Lima

Charles J. Amlaner

Sleep is a prominent behaviour in the lives of animals, but the unresponsiveness that characterizes sleep makes it dangerous. Mammalian sleep is composed of two neurophysiological states: slow wave sleep (SWS) and rapid-eye-movement (REM) sleep. Given that the intensity of stimuli required to induce an arousal to wakefulness is highest during deep SWS or REM sleep, mammals may be most vulnerable during these states. If true, then animals should selectively reduce deep SWS and REM sleep following an increase in the risk of predation. To test this prediction, we simulated a predatory encounter with 10 wild-caught Norway rats (Rattus norvegicus ...


Single Slide Sets To Accompany The Srs Basics Of Sleep Guide (Version 1.1), Charles Amlaner (Editor), Orfeu Buxton (Editor) Dec 2007

Single Slide Sets To Accompany The Srs Basics Of Sleep Guide (Version 1.1), Charles Amlaner (Editor), Orfeu Buxton (Editor)

Charles J. Amlaner

Contains 10 hour-long peer-reviewed lectures in Powerpoint based on the SRS basics of sleep guide.


Slide Sets To Accompany The Srs Basics Of Sleep Guide, Charles Amlaner (Editor), Orfeu Buxton (Editor) Dec 2006

Slide Sets To Accompany The Srs Basics Of Sleep Guide, Charles Amlaner (Editor), Orfeu Buxton (Editor)

Charles J. Amlaner

Contains 10 hour-long peer-reviewed lectures in Powerpoint based on the SRS basics of sleep guide.


A Phylogenetic Analysis Of The Correlates Of Sleep In Birds, Timothy Roth, John Lesku, Charles Amlaner, Steven Lima Nov 2006

A Phylogenetic Analysis Of The Correlates Of Sleep In Birds, Timothy Roth, John Lesku, Charles Amlaner, Steven Lima

Charles J. Amlaner

Quantitative comparative studies of sleep have focused exclusively on mammals. Such studies have repeatedly found strong relationships between the time spent in various sleep states and constitutive variables related to morphology, physiology, and life history. These studies influenced the development of several prominent hypotheses for the functions of sleep, but the applicability of these patterns and hypotheses to non-mammalian taxa is unclear. Here, we present the first quantitative analysis of sleep in a non-mammalian taxon (birds), focusing on the daily amount of time spent in slow-wave sleep (SWS) and rapid-eye movement (REM) sleep as determined by electrophysiological methods. We examined ...


A Phylogenetic Analysis Of Sleep Architecture In Mammals: The Integration Of Anatomy, Physiology, And Ecology, John Lesku, Timothy Roth, Charles Amlaner, Steven Lima Sep 2006

A Phylogenetic Analysis Of Sleep Architecture In Mammals: The Integration Of Anatomy, Physiology, And Ecology, John Lesku, Timothy Roth, Charles Amlaner, Steven Lima

Charles J. Amlaner

Among mammalian species, the time spent in the two main "architectural" states of sleep-slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep-varies greatly. Previous comparative studies of sleep architecture found that larger mammals, those with bigger brains, and those with higher absolute basal metabolic rates (BMR) tended to engage in less SWS and REM sleep. Species experiencing a greater risk of predation also exhibited less SWS and REM sleep. In all cases, however, these studies lacked a formal phylogenetic and theoretical framework and used mainly correlational analyses. Using independent contrasts and an updated data set, we extended existing approaches with path analysis ...


Asynchronous Eye Closure As An Anti-Predator Behavior In The Western Fence Lizard (Sceloporus Occidentalis), Christian Mathews, John Lesku, Stephen Lima, Charles Amlaner Feb 2006

Asynchronous Eye Closure As An Anti-Predator Behavior In The Western Fence Lizard (Sceloporus Occidentalis), Christian Mathews, John Lesku, Stephen Lima, Charles Amlaner

Charles J. Amlaner

Asynchronous eye closure (ASEC), one eye open while the other is closed, is a behavior observed in birds, some aquatic mammals, and reptiles. In birds and aquatic mammals, ASEC is associated with unihemispheric sleep wherein the cerebral hemisphere contralateral to (i.e. neurologically connected to) the closed eye sleeps while the other cerebral hemisphere remains awake with its associated eye open and functional. Evidence from birds suggests that ASEC is an important anti-predator adaptation to mediate the trade-off between the need to remain vigilant and the need to sleep. However, the anti-predator correlates of ASEC remain largely unstudied in other ...


The Evolution Of Sleep: A Phylogenetic Approach, John Lesku, Niels Rattenborg, Charles Amlaner Dec 2005

The Evolution Of Sleep: A Phylogenetic Approach, John Lesku, Niels Rattenborg, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Sleeping Under Risk Of Predation, Steven Lima, John Lesku, Neil Rattenborg, Charles Amlaner Sep 2005

Sleeping Under Risk Of Predation, Steven Lima, John Lesku, Neil Rattenborg, Charles Amlaner

Charles J. Amlaner

Every studied animal engages in sleep, and many animals spend much of their lives in this vulnerable behavioural state. We believe that an explicit description of this vulnerability will provide many insights into both the function and architecture (or organization) of sleep. Early studies of sleep recognized this idea, but it has been largely overlooked during the last 20 years. We critically evaluate early models that suggested that the function of sleep is antipredator in nature, and outline a new model in which we argue that whole-brain or 'blackout' sleep may be the safest way to sleep given a functionally ...


Phylogeny Of Sleep, Niels Rattenborg, Charles Amlaner Dec 2001

Phylogeny Of Sleep, Niels Rattenborg, Charles Amlaner

Charles J. Amlaner

No abstract provided.


The Evolutionary Significance Of Unihemispheric Slow Wave Sleep In Birds, Charles Amlaner Apr 2001

The Evolutionary Significance Of Unihemispheric Slow Wave Sleep In Birds, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Sleep-Wake Behavior Patterns And Eye Closure States In Juvenile Greater Rheas (Rhea Americana), Charles Amlaner, William Franklin, Christopher Ritzi, Steven Lima, Niels Rattenborg Apr 2001

Sleep-Wake Behavior Patterns And Eye Closure States In Juvenile Greater Rheas (Rhea Americana), Charles Amlaner, William Franklin, Christopher Ritzi, Steven Lima, Niels Rattenborg

Charles J. Amlaner

No abstract provided.


Unilateral Eye Closure And Interhemispheric Eeg Asymmetry During Sleep In The Pigeon (Columba Livia), Niels Rattenborg, Charles Amlaner, Steven Lima Dec 2000

Unilateral Eye Closure And Interhemispheric Eeg Asymmetry During Sleep In The Pigeon (Columba Livia), Niels Rattenborg, Charles Amlaner, Steven Lima

Charles J. Amlaner

Aquatic mammals (i.e., Cetaceans, eared seals and manatees) and birds show interhemispheric asymmetries (IA) in slow-wave sleep-related electroencephalographic (EEG) activity, suggesting that the depth of sleep differs between hemispheres. In birds, an association between unilateral eye closure and IA has been reported in five species from three orders (i.e., Galliformes, Charadriiformes, and Anseriformes). Moreover, unilateral eye closure has been observed during behaviorally defined sleep in 29 species from 13 avian orders, suggesting that birds in general display IA during sleep. Despite the apparent prevalence of unilateral eye closure and IA in birds, previous work did not detect A ...


Behavioral, Neurophysiological And Evolutionary Perspectives On Unihemispheric Sleep, Niels Rattenborg, Charles Amlaner, Steven Lima Nov 2000

Behavioral, Neurophysiological And Evolutionary Perspectives On Unihemispheric Sleep, Niels Rattenborg, Charles Amlaner, Steven Lima

Charles J. Amlaner

Several animals mitigate the fundamental conflict between sleep and wakefulness by engaging in unihemispheric sleep, a unique state during which one cerebral hemisphere sleeps while the other remains awake. Among mammals, unihemispheric sleep is restricted to aquatic species (Cetaceans, cared seals and manatees). in contrast to mammals, unihemispheric sleep is widespread in birds, and may even occur in reptiles. Unihemispheric sleep allows surfacing to breathe in aquatic mammals and predator detection in birds. Despite the apparent utility in being able to sleep unihemispherically, very few mammals sleep in this manner. This is particularly interesting since the reptilian ancestors to mammals ...


Eye States And Postures Of The Western Fence Lizard (Sceloporus Occidentalis), With Special Reference To Asynchronous Eye Closure And Behavioral Sleep, Christian Mathews, Charles Amlaner Aug 2000

Eye States And Postures Of The Western Fence Lizard (Sceloporus Occidentalis), With Special Reference To Asynchronous Eye Closure And Behavioral Sleep, Christian Mathews, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Design Of A Low Power Two-Channel Biotelemetry Transmitter And Demodulator For Use In Studies Of Sleep Behavior In Birds, Charles Amlaner, Brent Carr, Denis Curtis, Samuel Mcgarrah, Derek Sunderman Apr 1999

Design Of A Low Power Two-Channel Biotelemetry Transmitter And Demodulator For Use In Studies Of Sleep Behavior In Birds, Charles Amlaner, Brent Carr, Denis Curtis, Samuel Mcgarrah, Derek Sunderman

Charles J. Amlaner

Current technology in biomedical engineering has made it possible to remotely transmit, demodulate, store and accurately display a large suite of physiological electrical signals. By carefully selecting modern CMOS circuitry, the designer can fabricate micro-miniature, low power systems that ultimately can be hermetically sealed and implanted in a live, free-ranging animal. It was the lack of miniature, low power transmitter circuitry that has hampered some of the basic research questions on sleep patterns in free ranging animals, particularly birds and other small animals. We formulated a team of engineers in our Animal Sleep Research Laboratory to identify the critical technical ...


Half-Awake To The Risk Of Predation, Niels Rattenborg, Steven Lima, Charles Amlaner Feb 1999

Half-Awake To The Risk Of Predation, Niels Rattenborg, Steven Lima, Charles Amlaner

Charles J. Amlaner

Birds have overcome the problem of sleeping in risky situations by developing the ability to sleep with one eye open and one hemisphere of the brain awake. Such unihemispheric slow-wave sleep is in direct contrast to the typical situation in which sleep and wakefulness are mutually exclusive states of the whole brain. We have found that birds can detect approaching predators during unihemispheric slow-wave sleep, and that they can increase their use of unihemispheric sleep as the risk of predation increases. We believe this is the first evidence for an animal behaviourally controlling sleep and wakefulness simultaneously in different regions ...


Facultative Control Of Avian Unihemispheric Sleep Under The Risk Of Predation, Niels Rattenborg, Steven Lima, Charles Amlaner Dec 1998

Facultative Control Of Avian Unihemispheric Sleep Under The Risk Of Predation, Niels Rattenborg, Steven Lima, Charles Amlaner

Charles J. Amlaner

Birds and aquatic mammals are the only taxonomic groups known to exhibit unihemispheric slow-wave sleep (USWS). In aquatic mammals, USWS permits sleep and breathing to occur concurrently in water. However, the function of avian USWS has been unclear. Our study is based on the premise that avian USWS serves a predator detection function, since the eye contralateral to the awake hemisphere remains open during USWS. If USWS functions as a form of predator detection, then birds should be able to control both the proportion of slow-wave sleep composed of USWS and the orientation of the open eye in response to ...


Sleep, Sleep Disorders, And Biological Rhythms, Charles Amlaner, Robert Greene, Michael Hanson, Greg Greg Nichols, Naomi Rogers, Carol Thibodeau Dec 1998

Sleep, Sleep Disorders, And Biological Rhythms, Charles Amlaner, Robert Greene, Michael Hanson, Greg Greg Nichols, Naomi Rogers, Carol Thibodeau

Charles J. Amlaner

A module to help students to understand the nature and function of sleep and its effects on human health; to experience the process of scientific inquiry; and to recognize the role of science in society and the relationship of basic science and human health.


Behavior Patterns In Free-Ranging Black Rat Snakes, Charles Amlaner, James Withgott Aug 1997

Behavior Patterns In Free-Ranging Black Rat Snakes, Charles Amlaner, James Withgott

Charles J. Amlaner

While activity patterns of some animals are guided strictly by light-dark cycles or circadian rhythms, others show more flexible behavior. For ectothermic animals such as snakes, the temperature of their surroundings is a key factor in their physiology, behavior, and ecology. Various other factors, e.g., hunger, reproductive behavior, ecdysis, prey availability, and predation risk, also influence a snake's patterns of activity, often in conflicting and unpredictable ways. Studies of sleep patterns in such animals with variable and irregular activity may yield insights into the functions of sleep.


Natural History Note: Elaphe Obsoleta Obsoleta (Black Rat Snake) - Foraging, James Withgott, Charles Amlaner Dec 1995

Natural History Note: Elaphe Obsoleta Obsoleta (Black Rat Snake) - Foraging, James Withgott, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Monitoring Body Temperature And Nocturnal Activity Of Snakes With Implanted Transmitters, James Withgott, Charles Amlaner Dec 1995

Monitoring Body Temperature And Nocturnal Activity Of Snakes With Implanted Transmitters, James Withgott, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Natural History Note: Elaphe Obsoleta Obsoleta (Black Rat Snake) - Response To Fire, James Withgott, Charles Amlaner Dec 1995

Natural History Note: Elaphe Obsoleta Obsoleta (Black Rat Snake) - Response To Fire, James Withgott, Charles Amlaner

Charles J. Amlaner

No abstract provided.


Transmitter Implantation Techniques In Black Rat Snakes, Charles Amlaner, James Withgott Dec 1995

Transmitter Implantation Techniques In Black Rat Snakes, Charles Amlaner, James Withgott

Charles J. Amlaner

No abstract provided.


Biotelemetry Xiii: Proceedings Of The Thirteenth International Symposium On Biotelemetry, Cristina Cristalli (Editor), Charles Amlaner (Editor), Michael Neuman (Editor) Dec 1994

Biotelemetry Xiii: Proceedings Of The Thirteenth International Symposium On Biotelemetry, Cristina Cristalli (Editor), Charles Amlaner (Editor), Michael Neuman (Editor)

Charles J. Amlaner

Proceedings of the Thirteenth International Symposium on Biotelemetry held at Williamsburg Lodge, Williamsburg, Virginia, March 26-31, 1995


Avian Sleep, Charles Amlaner, Nigel Ball Dec 1993

Avian Sleep, Charles Amlaner, Nigel Ball

Charles J. Amlaner

No abstract provided.


Biotelemetry And Hard Wire Recording Of Sleep Eeg's In Northern Bobwhite Quail (Colinus Virginanus), Nigel Ball, Charles Amlaner, Douglas Schmidt, James Shaffery Dec 1992

Biotelemetry And Hard Wire Recording Of Sleep Eeg's In Northern Bobwhite Quail (Colinus Virginanus), Nigel Ball, Charles Amlaner, Douglas Schmidt, James Shaffery

Charles J. Amlaner

No abstract provided.


Auditory Tele-Stimulated Arousal Thresholds During Sleep In Glaucous-Winged Gulls (Larus Glaucescens), Jim Nestler, Nigel Ball, Charles Amlaner Dec 1992

Auditory Tele-Stimulated Arousal Thresholds During Sleep In Glaucous-Winged Gulls (Larus Glaucescens), Jim Nestler, Nigel Ball, Charles Amlaner

Charles J. Amlaner

No abstract provided.