Richard Stephenson

faculty_img Academic Title: Associate Professor

Campus: St. George

CSB Appointment: Full

Primary Undergraduate Department:
Cell & Systems Biology

Graduate Programs:
Cell & Systems Biology

Titles and Honors:


Academic or Administrative Appointments:


Education:
Ph.D. University of Birmingham 1987, B.Sc. University of Sheffield 1982

 

Mailing Address
Department of Cell & Systems Biology
University of Toronto
25 Harbord St.
Toronto, ON M5S 3G5
Canada
 

 

Contact Information
Office phone: 416-978-3491 
Office: RW 325C 
Lab: RW 325 / 327 
Lab phone: 416-946-7237 
Email: richard.stephenson@utoronto.ca 
URL:

 

Research Areas
Animal Biology
Neurobiology
Physiology
Psychology & Behavior

 

Research

Research in this laboratory is currently focused on regulatory and functional aspects of sleep in the mollusc Lymnaea stagnalis. Video tracking and motion analysis, neurophysiological techniques and quantitative modeling are brought to bear on questions concerning the links between sleep-wake behaviour, animal energetics and the physiology of tissues and single identified neurons. Previous research in this laboratory has mainly looked at rodent sleep but the sheer complexity of sleep in mammals represents a major obstacle to real progress. We have therefore turned to a simple model system to facilitate the discovery of fundamental insights in the adaptive significance of sleep.

 

Publications

2013

Top
Statistical properties of sleep-wake behavior in the rat and their relation to circadian and ultradian phases.Stephenson R, Famina S, Caron AM, Lim J.Sleep 2013 Sep;36(9):1377-90
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A simple model for the origin of quasiperiodic ultradian rhythms in sleep-wake state in the rat.Stephenson R.Commun Integr Biol 2013 Jan;6(1):e22433
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2012

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Sleep-wake behavior in the rat: ultradian rhythms in a light-dark cycle and continuous bright light.Stephenson R, Lim J, Famina S, Caron AM, Dowse HB.J. Biol. Rhythms 2012 Dec;27(6):490-501
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2011

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Sleep homeostasis: Progress at a snail's pace.Stephenson R.Commun Integr Biol 2011 Jul;4(4):446-9
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Behavioural evidence for a sleep-like quiescent state in a pulmonate mollusc, Lymnaea stagnalis (Linnaeus).Stephenson R, Lewis V.J. Exp. Biol. 2011 Mar;214(Pt 5):747-56
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2010

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Energy expenditure is affected by rate of accumulation of sleep deficit in rats.Caron AM, Stephenson R.Sleep 2010 Sep;33(9):1226-35
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2009

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Automated analysis of sleep-wake state in rats.Stephenson R, Caron AM, Cassel DB, Kostela JC.J. Neurosci. Methods 2009 Nov;184(2):263-74
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2007

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Prolonged deprivation of sleep-like rest raises metabolic rate in the Pacific beetle cockroach, Diploptera punctata (Eschscholtz).Stephenson R, Chu KM, Lee J.J. Exp. Biol. 2007 Jul;210(Pt 14):2540-7
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Circadian rhythms and sleep-related breathing disorders.Stephenson R.Sleep Med. 2007 Sep;8(6):681-7
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2006

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The effect of time of day on apnoea index in the sleeping rat.Stephenson R, Horner RL.Respir Physiol Neurobiol 2006 Dec;154(3):351-5
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2005

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A theoretical analysis of diving performance in the Weddell seal (Leptonychotes weddelli).Stephenson R.Physiol. Biochem. Zool. 2005 Sep-Oct;78(5):782-800
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A visual aid for computer-based analysis of sleep-wake state in rats.Mileva-Seitz VR, Louis RP, Stephenson R.J. Neurosci. Methods 2005 Oct;148(1):43-8
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Physiological control of diving behaviour in the Weddell seal Leptonychotes weddelli: a model based on cardiorespiratory control theory.Stephenson R.J. Exp. Biol. 2005 May;208(Pt 10):1971-91
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2004

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A theoretical study of the effect of circadian rhythms on sleep-induced periodic breathing and apnoea.Stephenson R.Respir Physiol Neurobiol 2004 Feb;139(3):303-19
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Design and validation of a computer-based sleep-scoring algorithm.Louis RP, Lee J, Stephenson R.J. Neurosci. Methods 2004 Feb;133(1-2):71-80
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2003

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Do circadian rhythms in respiratory control contribute to sleep-related breathing disorders?.Stephenson R.Sleep Med Rev 2003 Dec;7(6):475-90
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2002

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Theoretical and practical considerations in the application of whole body plethysmography to sleep research.Stephenson R, Gucciardi EJ.Eur. J. Appl. Physiol. 2002 Jul;87(3):207-19
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2001

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Circadian rhythms and sleep have additive effects on respiration in the rat.Stephenson R, Liao KS, Hamrahi H, Horner RL.J. Physiol. (Lond.) 2001 Oct;536(Pt 1):225-35
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Selected Contribution: Regulation of sleep-wake states in response to intermittent hypoxic stimuli applied only in sleep.Hamrahi H, Stephenson R, Mahamed S, Liao KS, Horner RL.J. Appl. Physiol. 2001 Jun;90(6):2490-501
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Respiratory control in neonatal mice with NADPH oxidase deficiency.Kazemian P, Stephenson R, Yeger H, Cutz E.Respir Physiol 2001 Jun;126(2):89-101
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2000

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Effects of hypoxia and hypercapnia on circadian rhythms in the golden hamster (Mesocricetus auratus).Jarsky TM, Stephenson R.J. Appl. Physiol. 2000 Dec;89(6):2130-8
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A model of the chemoreflex control of breathing in humans: model parameters measurement.Duffin J, Mohan RM, Vasiliou P, Stephenson R, Mahamed S.Respir Physiol 2000 Mar;120(1):13-26
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Circadian rhythms in the chemoreflex control of breathing.Stephenson R, Mohan RM, Duffin J, Jarsky TM.Am. J. Physiol. Regul. Integr. Comp. Physiol. 2000 Jan;278(1):R282-6
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1998

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Circadian rhythms in diving behavior and ventilatory response to asphyxia in canvasback ducks.Woodin M, Stephenson R.Am. J. Physiol. 1998 Mar;274(3 Pt 2):R686-93
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1997

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Day-night differences in the respiratory response to hypercapnia in awake adult rats.Peever JH, Stephenson R.Respir Physiol 1997 Sep;109(3):241-8
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1995

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Respiratory and plumage gas volumes in unrestrained diving ducks (Aythya affinis).Stephenson R.Respir Physiol 1995 May;100(2):129-37
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1994

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Regional cerebral blood flow during submergence asphyxia in Pekin duck.Stephenson R, Jones DR, Bryan RM.Am. J. Physiol. 1994 Apr;266(4 Pt 2):R1162-8
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1992

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Metabolic responses to forced dives in Pekin duck measured by indirect calorimetry and 31P-MRS.Stephenson R, Jones DR.Am. J. Physiol. 1992 Dec;263(6 Pt 2):R1309-17
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