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Biochemistry, Biophysics, and Structural Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Animal Sciences

Charles J. Amlaner

Vigilance

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Articles 1 - 3 of 3

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

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 ...


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 ...