Faculty Profile

Charles A. Czeisler, PhD, MD, FRCP

Charles A. Czeisler, PhD, MD
Baldino Professor of Sleep Medicine, Harvard Medical School
Senior Physician, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital
Affiliated Faculty, Department of Neurobiology, Harvard Medical School

Administrative Title(s)

Chief, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital
Director, Division of Sleep Medicine, Harvard Medical School

Other Affiliation(s)

Affiliated Faculty, Health Sciences and Technology, Harvard-Massachusetts Institute of Technology
Member, Human Factors and Performance Team, National Space Biomedical Research Institute

See publications


Division of Sleep and Circadian Disorders, Brigham and Women's Hospital
221 Longwood Ave, Room 438A
Boston, MA 02115

Phone 617-732-4013
Phone 617-732-5924 (Administrative Assistant)
Fax 617-732-4015

Email charles_czeisler@hms.harvard.edu
Email cacadmin@rics.bwh.harvard.edu

Society Memberships

Sleep Research Society
American Academy of Sleep Medicine
Society for Research on Biological Rhythms
American Physiological Society
Society for Neuroscience
International Society for Chronobiology
American Association for the Advancement of Science

Research Unit(s)

Circadian Group, Division of Sleep Medicine, Brigham and Women's Hospital
Harvard Work Hours, Health and Safety Group, Harvard Medical School
Member of the faculty of the Harvard Medical School Program in Neuroscience

Research Interests

My laboratory research is focused on understanding the neurobiology of the human circadian pacemaker, located in the suprachiasmatic nucleus (SCN) of the hypothalamus, and its interaction with the sleep homeostat, and on applying that knowledge to clinical medicine and occupational health. We are examining the role of the pineal hormone melatonin in the organization of sleep and circadian rhythms. We are investigating the physiological mechanism underlying photic resetting of the human circadian pacemaker, having shown that some blind people without sight can retain normal circadian responsiveness to light. We are now investigating how the timing, duration, intensity and wavelength of light affects its circadian resetting capacity, which is mediated through intrinsically photosensitive retinal ganglion cells containing the novel photopigment melanopsin. Current research is aimed at functional determination of the photoreceptor(s) responsible for circadian vision in humans, on adaptation of circadian photoreceptors and on the after-effects of entrainment on circadian period in humans. We are investigating how circadian and homeostatic processes interact to regulate sleep and neurobiological function during wakefulness. Other ongoing research in the lab includes examining novel wakefulness- and sleep-promoting countermeasures, the effect of exercise on the circadian pacemaker, fMRI of the sleep deprived brain, the influence of aging on sleep and circadian rhythms, the influence of chronic sleep restriction on human performance, the influence of space flight on sleep and circadian rhythms and the application of our research to night workers-including medical residents and police-through the work of the Harvard Work Hours, Health and Safety Group.


Steven H. Strogatz, PhD        [1986 - 1989]
Theresa L. Shanahan, MD      [1990 - 1992]
Joanne Waldstreicher, MD    [1990 - 1992]
Ghada El-Hajj-Fuleihan, MD    [1991 - 1994]
Elizabeth B. Klerman, MD, PhD      [1991 - 1995]
Diane B. Boivin, MD, PhD      [1992 - 1997]
David Neri, PhD         [1993 - 1995]
Jamie M. Zeitzer, PhD          [1994 - 1999]
James K. Wyatt, PhD, D ABSM     [1995 - 1998]
Todd Horowitz, PhD         [1996 - 2000]
Sat Bir Khalsa, PhD          [1996 - 1998]
Megan Jewett, PhD**          [1997 - 1999]
Angela Ritz-De Cecco, PhD      [1997 - 2004]
Kenneth P. Wright Jr., PhD     [1997 - 2000]
Jeanne Duffy, MBA, PhD**     [1998 - 2000]
Scott P. Grady, MD, PhD      [1999 - 2002]
Claude Gronfier, PhD          [1999 - 2003]
Laura K. Barger, PhD**         [2000 - Present]
Steven Lockley, PhD          [2000 - 2003]
Joshua J. Gooley, PhD**     [2001 – 2002 / 2005 - Present]
Shana E. McCormack, MD      [2001 - Present]
John Cronin, MD**          [2002 - 2004]
Joseph T. Hull, PhD          [2002 - Present]
Nayantara Santhi, PhD**     [2002 - 2010]
Kurt A. Smith, MD          [2002 - 2005]
Anne-Marie Chang, PhD**     [2003 - 2011]
Frank A.J.L. Scheer, PhD      [2003 - 2005]
Martin W. Schoen, MD          [2003 - 2006]
Erin E. Flynn-Evans**         [2004 - Present]
Julie Marie Gottselig, PhD     [2004 – 2006]
Sean W. Cain, PhD          [2006 – 2012]
Christopher Carello, PhD**     [2006 – 2007]
Daniel Cohen, MD**         [2006 - 2011]
Melanie Rüger, PhD         [2007 - Present]
Josna Adusumilli, MD        [2007- Present]


William C. Dement, MD, PhD
Elliott D. Weitzman, MD

Research Funding

NIH R01 (National Heart, Lung & Blood Institute) Principal Investigator
"Bright light treatment of shift rotation insomnia"

NIH R01 (National Institute of Mental Health) Principal Investigator
"Treatment of circadian sleep disorders with bright light"

NIH T32 (National Heart, Lung & Blood Institute) Program Director
"Training in sleep, circadian and respiratory neurobiology"

CDC R-01 (National Institute of Occupational Safety and Health) Principal Investigator
"Sleep Disorders Management, Health and Safety in Police"

National Space Biomedical Research Institute Team Leader
"Human Performance Factors, Sleep and Chronobiology Team"

National Space Biomedical Research Institute, Principal Investigator
"Circadian entrainment, sleep-wake regulation and performance during space flight"

NIH R-01 (National Heart, Lung & Blood Institute) Principal Investigator
"Adaptation of Circadian Responses to Light Treatment"

NIH R-01 (National Institute of Complementary and Alternative Medicine) Principal Investigator
"Mechanism Underlying the Effects of Blue Light in Humans"

Department of Justice (National Institute of Justice) Principal Investigator
"Testing the Effectiveness of a Comprehensive Fatigue Management Program for the Boston Police"

NIH P01 (National Institute on Aging) Principal Investigator
"Sleep, aging and circadian rhythm disorders"

National Aeronautics & Space Administration, Principal Investigator
Flight-Based Protocol Aboard Space Shuttle: "Sleep-Wake Actigraphy and Light
Exposure During Spaceflight"

NIH R01 (National Institute of Neurological Disorders and Stroke) Principal Investigator
"Circadian adaptation to non-24-hour sleep-wake schedules"

Air Force Office of Scientific Research, Principal Investigator
"Optimizing the Assessment of Circadian and Sleep/Wake Regulatory Determinants of Human Performance Through State-Of-Art Analysis of Electroencephalogram, Ocular Activity and Motor Activity"

Air Force Office of Scientific Research Co-Principal Investigator
"Interaction of chronic sleep restriction and circadian misalignment on sleep and
neuro-cognitive performance: developing a new model of sleep homeostasis"

NIH R01 (National Institute of Neurological Disorders and Stroke) Principal Investigator
"Photic and nonphotic input to the human circadian system"


Current courses:
Circadian Biology: From Cellular Oscillators to Sleep Regulation
Properties, mechanisms, and functional roles of circadian (daily) rhythms in organisms ranging from unicells to mammals. Cellular and molecular components, regulation of gene expression and physiological functions, genetic and biochemical analyses of circadian rhythms, and neurobiology of the mammalian circadian pacemaker. Mathematics and modeling of oscillatory systems and applications to circadian rhythms. Experimental studies of human rhythms, including the sleep-wake cycle and hormone rhythms, with applications to sleep disorders. Find more information on the course website.

Charles A. Czeisler, Ph.D., M.D., F.R.C.P. is the Baldino Professor of Sleep Medicine, Director of the Division of Sleep Medicine at Harvard Medical School and Chief of the Division of Sleep Medicine in the Department of Medicine at Brigham and Women’s Hospital in Boston, Massachusetts. He is an Affiliate Faculty Member in the Neuroscience Program at Harvard Medical School and the Health Science and Technology Program at Harvard Medical School/Massachusetts Institute of Technology.

Dr. Czeisler graduated magna cum laude with a degree in Biochemistry and Molecular Biology from Harvard College, where he was inducted into Phi Beta Kappa in 1999. He received his Ph.D. in Neuro- and Bio-behavioral Sciences and his M.D. from Stanford University. He is a recipient of the Robert R.J. Hilker Award in Occupational Medicine (1991); Aschoff’s Rule (2001); the E.H. Ahrens, Jr. Lecture Award from the Association for Patient Oriented Research (2002); the William C. Dement Academic Achievement Award from the American Academy of Sleep Medicine (2002); the NIOSH Director’s Award for Scientific Leadership in Occupational Safety And Health for his research on resident work hours and safety (2005); the National Sleep Foundation 2006 Healthy Sleep Community Award (Harvard Work Hours and Health and Safety Group); the 10th Annual J. Gerald Reves Duke Heart Center Lecture Award from Duke Medical Center (2007); the Dorcas Cummings Memorial Lecture Award from Cold Spring Harbor Laboratory (2007); the National Sleep Foundation Lifetime Achievement Award (2008) and the Adrian Medal from the Royal Society of Medicine, London (2008) and the Sleep Research Society Distinguished Scientist Award (2008). He is a past President of the Sleep Research Society where he chaired the Presidential Task Force on Sleep and Public Policy; a Fellow of the American Society for Clinical Investigation and of the Association of American Physicians; a Diplomate of the American Board of Sleep Medicine; a Fellow of the Royal College of Physicians (London) and an elected member of the American Clinical and Climatological Association.

Dr. Czeisler has more than 30 years’ experience in the field of basic and applied research on the physiology of the human circadian timing system and its relationship to the sleep-wake cycle. For more than a decade he served as Team Leader of the Human Performance Factors, Sleep and Chronobiology Team of NASA’s National Space Biomedical Research Institute, which is responsible for developing sleep-wake schedule guidelines and related countermeasures for use by NASA astronauts and mission control personnel during space exploration. Dr. Czeisler has served on and consulted to a number of national and international advisory committees, including the National Institutes of Health, the Institute of Medicine, the National Academy of Sciences, the Sleep Research Society, the Nuclear Regulatory Commission, the Air Force Office of Scientific Research, the Air Transport Association and the Federal Motor Carrier Safety Administration of the US Department of Transportation.

Dr. Czeisler has published over 120 original reports in peer-reviewed journals, more than 75 review articles, 5 books/monographs and numerous research abstracts; he has been a member of the editorial boards of American Journal of Medicine, Journal of Biological Rhythms, and Sleep. He has been Keynote Speaker at annual meetings of the Japanese Society for Sleep Research (1996), the Association of Professional Sleep Societies (1997), the Society for Research on Biological Rhythms (2002), the Patient Safety Research Conference, Agency for Healthcare Research and Quality (2003), the Committee of Interns & Residents (2005), the American Clinical and Climatological Association (2005), the X International Congress, Brazilian Sleep Research Society (2005), and the New Zealand Resident Doctors Association Professional Conference on Safer Working Hours in Medicine (2005). Dr. Czeisler has delivered lectures at the World Congress of Chronobiology in Sapporo (2003), the Second International Forum on Sleep Disorders, Sanofi Aventis, Paris (2004), Distinguished Leader in Medicine Lecture, Dalhousie University, Halifax, Canada (2006), the 5th Congress of the World Federation of Sleep Research and Sleep Medicine Societies in Australia (2007) and the Harvard Medical School Dubai Center Institute for Postgraduate Education & Research, Dubai (2007).

Selected Publications

Klerman EB, Wang W, Duffy JF, Dijk DJ, Czeisler CA, Kronauer RE. Survival analysis indicates that age-related decline in sleep continuity occurs exclusively during NREM sleep.
Neurobiol Aging. 2013 Jan;34(1):309-18. [PMID: 22727943]

Rüger M, St Hilaire MA, Brainard G, Khalsa SB, Kronauer RE, Czeisler CA, Lockley SW. Human phase response curve to a single 6.5-h pulse of short-wavelength light.
J Physiol. 2012 Nov 26. [PMID: 23090946]

Gooley JJ, Ho Mien I, St Hilaire MA, Yeo SC, Chua EC, van Reen E, Hanley CJ, Hull JT, Czeisler CA, Lockley SW. Melanopsin and rod-cone photoreceptors play different roles in mediating pupillary light responses during exposure to continuous light in humans.
J Neurosci. 2012 Oct 10;32(41):14242-53. [PMID: 23055493]

Lim AS, Chang AM, Shulman JM, Raj T, Chibnik LB, Cain SW, Rothamel K, Benoist C, Myers AJ, Czeisler CA, Buchman AS, Bennett DA, Duffy JF, Saper CB, De Jager PL. A common polymorphism near PER1 and the timing of human behavioral rhythms.
Ann Neurol. 2012 Sep;72(3):324-34. [PMID: 23034908]

Berger M, Varvarigou V, Rielly A, Czeisler CA, Malhotra A, Kales SN. Employer-mandated sleep apnea screening and diagnosis in commercial drivers.
J Occup Environ Med. 2012 Aug;54(8):1017-25. [PMID: 22850349]

Pomplun M, Silva EJ, Ronda JM, Cain SW, Münch MY, Czeisler CA, Duffy JF. The effects of circadian phase, time awake, and imposed sleep restriction on performing complex visual tasks: evidence from comparative visual search.
J Vis.  2012 Jul 26;12(7). [PMID: 22836655]

Chang AM, Santhi N, St Hilaire M, Gronfier C, Bradstreet DS, Duffy JF, Lockley SW, Kronauer RE, Czeisler CA. Human responses to bright light of different durations.
J Physiol. 2012 Jul 1;590(Pt 13):3103-12 [PMID: 22526883]

St Hilaire MA, Gooley JJ, Khalsa SB, Kronauer RE, Czeisler CA, Lockley SW. Human phase response curve to a 1 h pulse of bright white light.
J Physiol. 2012  Jul 1;590(Pt 13):3035-45. [PMID: 22547633]

Anderson C, Sullivan JP, Flynn-Evans EE, Cade BE, Czeisler CA, Lockley SW. Deterioration of neurobehavioral performance in resident physicians during repeated exposure to extended duration work shifts.
Sleep. 2012 Aug 1;35(8):1137-46. [PMID: 22851809]

Buxton OM, Cain SW, O'Connor SP, Porter JH, Duffy JF, Wang W, Czeisler CA, Shea SA. Adverse metabolic consequences in humans of prolonged sleep restriction  combined with circadian disruption.
Sci Transl Med. 2012 Apr 11;4(129):129ra43. [PMID: 22496545]

Dijk DJ, Duffy JF, Silva EJ, Shanahan TL, Boivin DB, Czeisler CA. Amplitude reduction and phase shifts of melatonin, cortisol and other circadian rhythms after a gradual advance of sleep and light exposure in humans.
PLoS One. 2012;7(2):e30037 [PMID: 22363414]

Rajaratnam SM, Barger LK, Lockley SW, Shea SA, Wang W, Landrigan CP, O'Brien CS, Qadri S, Sullivan JP, Cade BE, Epstein LJ, White DP, Czeisler CA; Harvard Work Hours, Health and Safety Group. Sleep disorders, health, and safety in police officers.
JAMA. 2011 Dec 21;306(23):2567-78 [PMID: 22187276]

Czeisler CA. Impact of sleepiness and sleep deficiency on public health-utility of biomarkers.
J Clin Sleep Med. 2011 Oct 15;7(5 Suppl):S6-8.[PMID: 22003334]

Mullington JM, Czeisler CA, Goel N, Krueger JM, Balkin TJ, Johns M, Shaw PJ. Panel discussion: current status of measuring sleepiness.
J Clin Sleep Med. 2011 Oct 15;7(5 Suppl):S22-5. [PMID: 22003325]

Phillips AJ, Czeisler CA, Klerman EB. Revisiting spontaneous internal desynchrony using a quantitative model of sleep physiology.
J Biol Rhythms. 2011  Oct;26(5):441-53. [PMID: 21921298]

Duffy JF, Cain SW, Chang AM, Phillips AJ, Münch MY, Gronfier C, Wyatt JK, Dijk DJ, Wright KP  Jr, Czeisler CA. Sex difference in the near-24-hour intrinsic period of the human circadian  timing system.
Proc Natl Acad Sci U S A. 2011 Sep 13;108 Suppl 3:15602-8. Epub 2011 May 2. [PMID: 21536890]

Chang AM, Scheer FA, Czeisler CA. The human circadian system adapts to prior photic history.
J Physiol. 2011 Mar 1;589(Pt 5):1095-102. Epub 2011 Jan 10. [PMID: 21224217]

Gooley JJ, Chamberlain K, Smith KA, Khalsa SB, Rajaratnam SM, Van Reen E, Zeitzer JM, Czeisler CA, Lockley SW. Exposure to room light before bedtime suppresses melatonin onset and shortens melatonin duration in humans.
J Clin Endocrinol Metab. 2011 Mar;96(3):E463-72. Epub 2010 Dec 30. [PMID: 21193540]

Nurok M, Czeisler CA, Lehmann LS. Sleep deprivation, elective surgical procedures, and informed consent.
N Engl J Med. 2010 Dec 30;363(27):2577-9. [PMID: 21190452]

Gordon JA, Alexander EK, Lockley SW, Flynn-Evans E, Venkatan SK, Landrigan CP, Czeisler CA; Harvard Work Hours, Health, and Safety Group (Boston, Massachusetts). Does simulator-based clinical performance correlate with actual hospital behavior? The effect of extended work hours on patient care provided by  medical interns.
Acad Med. 2010 Oct;85(10):1583-8. [PMID: 20881679]

Jung CM, Ronda JM, Czeisler CA, Wright KP Jr. Comparison of sustained attention assessed by auditory and visual psychomotor vigilance tasks prior to and during sleep deprivation.
J Sleep Res. 2011 Jun;20(2):348-55. Epub 2010 Aug 31. [PMID: 20819145]

Cain SW, Dennison CF, Zeitzer JM, Guzik AM, Khalsa SB, Santhi N, Schoen MW, Czeisler CA, Duffy JF. Sex differences in phase angle of entrainment and melatonin amplitude in humans.
J Biol Rhythms. 2010 Aug;25(4):288-96. [PMID: 20679498]

Blum AB, Raiszadeh F, Shea S, Mermin D, Lurie P, Landrigan CP, Czeisler CA. US public opinion regarding proposed limits on resident physician work hours.
BMC Med. 2010 Jun 1;8:33. [PMID: 20515479]

Grady S, Aeschbach D, Wright KP Jr, Czeisler CA. Effect of modafinil on impairments in neurobehavioral performance and learning associated with extended  wakefulness and circadian misalignment.
Neuropsychopharmacology. 2010 Aug;35(9):1910-20. Epub 2010 May 26. [PMID: 20505660]

Jung CM, Khalsa SB, Scheer FA, Cajochen C, Lockley SW, Czeisler CA, Wright KP Jr. Acute effects of bright light exposure on cortisol levels.
J Biol Rhythms. 2010 Jun;25(3):208-16. [PMID: 20484692]

Gooley JJ, Rajaratnam SM, Brainard GC, Kronauer RE, Czeisler CA, Lockley SW.  Spectral responses of the human circadian system depend on the irradiance and duration of exposure to light.
Sci Transl Med. 2010 May 12;2(31):31ra33. [PMID: 20463367]

Cohen DA, Wang W, Wyatt JK, Kronauer RE, Dijk DJ, Czeisler CA, Klerman EB. Uncovering residual effects of chronic sleep loss on human performance.
Sci Transl Med. 2010 Jan 13;2(14):14ra3. [PMID: 20371466]

Münch M, Silva EJ, Ronda JM, Czeisler CA, Duffy JF. EEG sleep spectra in older adults across all circadian phases during NREM sleep.
Sleep. 2010 Mar;33(3):389-401. [PMID: 20337198]

Czeisler CA. Wake-promoting therapeutic medications not an appropriate alternative to implementation of safer work schedules for resident physicians.
Mayo Clin Proc. 2010 Mar;85(3):302-3; author reply 303. [PMID: 20194158]

Duffy JF, Czeisler CA. Effect of Light on Human Circadian Physiology.
Med Clin. 2009 Jun;4(2):165-177. [PMID: 20161220]

Czeisler CA, Walsh JK, Wesnes KA, Arora S, Roth T. Armodafinil for treatment of excessive sleepiness associated with shift work disorder: a randomized controlled study.
Mayo Clin Proc. 2009 Nov;84(11):958-72. [PMID: 19880686]

Rothschild JM, Keohane CA, Rogers S, Gardner R, Lipsitz SR, Salzberg CA, Yu T,
Yoon CS, Williams DH, Wien MF, Czeisler CA, Bates DW, Landrigan CP. Risks of
complications by attending physicians after performing nighttime procedures.
JAMA. 2009 Oct 14;302(14):1565-72. [PMID: 19826026]

Czeisler CA. Medical and genetic differences in the adverse impact of sleep
loss on performance: ethical considerations for the medical profession.
Trans Am Clin Climatol Assoc. 2009;120:249-85. [PMID: 19768182]

Lipton J, Megerian JT, Kothare SV, Cho YJ, Shanahan T, Chart H, Ferber R,
Adler-Golden L, Cohen LE, Czeisler CA, Pomeroy SL. Melatonin deficiency and
disrupted circadian rhythms in pediatric survivors of craniopharyngioma.
Neurology. 2009 Jul 28;73(4):323-5. [PMID: 19636054]

Aeschbach D, Lockyer BJ, Dijk DJ, Lockley SW, Nuwayser ES, Nichols LD,
Czeisler CA. Use of transdermal melatonin delivery to improve sleep maintenance
during daytime.
Clin Pharmacol Ther. 2009 Oct;86(4):378-82. Epub 2009 Jul 15.[PMID: 19606092]

Duffy JF, Willson HJ, Wang W, Czeisler CA. Healthy older adults better
tolerate sleep deprivation than young adults.
J Am Geriatr Soc. 2009 Jul;57(7):1245-51. Epub 2009 Apr 30. [PMID: 19460089]

Santhi N, Aeschbach D, Horowitz TS, Czeisler CA. The impact of sleep timing and bright light exposure on attentional impairment during night work.
J Biol Rhythms. 2008 Aug;23(4):341-52. [PMID: 18663241]

Zaidi FH, Hull JT, Peirson SN, Wulff K, Aeschbach D, Gooley JJ, Brainard GC, Gregory-Evans K, Rizzo III JF, Czeisler CA, Foster RG, Moseley MJ, Lockley SW. Short-wavelength light sensitivity of circadian, pupillary, and visual awareness in humans lacking an outer retina.
Current Biology. 2007 Dec 18;17(24):2122-8. [PMID: 18082405]

Gronfier C, Wright KP Jr, Kronauer RE, Czeisler CA.  Entrainment of the human circadian pacemaker to longer-than-24-h days.
Proc Natl Acad Sci U S A. 2007 May 22;104(21):9081-6. Epub 2007 May 14. [PMID: 17502598] 

St Hilaire MA, Klerman EB, Khalsa SB, Wright KP Jr, Czeisler CA, Kronauer RE. Addition of a non-photic component to a light-based mathematical model of the human circadian pacemaker.
J Theor Biol. 2007 Aug 21;247(4):583-99. Epub 2007 Apr 4. [PMID: 17531270]

Barger LK, Ayas NT, Cade BE, Cronin JW, Rosner B, Speizer FE, Czeisler CA. Impact of extended-duration shifts on medical errors, adverse events, and attentional failures.
PLoS Med. 2006 Dec;3(12):e487. [PMID: 17194188]

Ayas NT, Barger LK, Cade BE, Hashimoto DM, Rosner B, Cronin JW, Speizer FE, Czeisler CA. Extended work duration and the risk of self-reported percutaneous injuries in interns.
JAMA. 2006 Sep 6;296(9):1055-62. [PMID: 16954484]
Wyatt JK, Dijk DJ, Ritz-de Cecco A, Ronda JM, Czeisler CA.  Sleep-facilitating effect of exogenous melatonin in healthy young men and women is circadian-phase dependent.
Sleep. 2006 May 1;29(5):609-18. [PMID: 16774150]

Czeisler CA. The Gordon Wilson Lecture: Work Hours, Sleep and Patient Safety in Residency Training.
Trans Am Clin Climatol Assoc. 2006; 117:159-189.

Lockley SW, Landrigan CP, Barger LK, Czeisler CA. When Policy Meets Physiology: The Challenge of Reducing Resident Work Hours.
Clin Orthop Relat Res. 2006 Aug;449:116-27. [PMID: 16770285]

Landrigan CP, Barger LK, Cade BE, Ayas NT, Czeisler CA. Interns' compliance with accreditation council for graduate medical education work-hour limits.
JAMA. 2006 Sep 6;296(9):1063-70. [PMID: 16954485]

Czeisler CA. Sleep Deficit. The Performance Killer. A conversation with Harvard Medical School Professor Charles A. Czeisler. Fryer B, editor.
Harvard Business Review. 2006 Oct;84(10):53-9, 148. [PMID: 17040040]

Duffy JF, Zeitzer JM, Czeisler CA. Decreased sensitivity to phase-delaying effects of moderate intensity light in older subjects.
Neurobiol Aging. 2007 May;28(5):799-807. Epub 2006 Apr 18. [PMID: 16621166]

Wright KP Jr, Hull JT, Hughes RJ, Ronda JM, Czeisler CA. Sleep and wakefulness out of phase with internal biological time impairs learning in humans.
J Cognitive Neurosci. 2006 Apr;18(4):508-21. [PMID: 16768357]

Grady SP, Nishino S, Czeisler CA, Hepner D, Scammell TE. Diurnal variation in CSF orexin-A in healthy male subjects.
Sleep. 2006 Mar 1;29(3):295-7. [PMID: 16553014]

Rothschild JM, Hurley AC, Landrigan CP, Cronin JW, Martell-Waldrop K, Foskett C, Burdick E, Czeisler CA, Bates DW. Recovery from medical errors: the critical care nursing safety net.
Jt Comm J Qual Patient Saf. 2006 Feb;32(2):63-72. [PMID: 16568919]

Lockley SW, Evans EE, Scheer FA, Brainard GC, Czeisler CA, Aeschbach D. Short-wavelength sensitivity for the direct effects of light on alertness, vigilance, and the waking electroencephalogram in humans.
Sleep. 2006 Feb 1;29(2):161-8. [PMID: 16494083]

Scheer FA, Zeitzer JM, Ayas NT, Brown R, Czeisler CA, Shea SA. Reduced sleep efficiency in cervical spinal cord injury; association with abolished night time melatonin secretion.
Spinal Cord. 2006 Feb;44(2):78-81. [PMID: 16130027]

Wertz AT, Ronda JM, Czeisler CA, Wright KP Jr. Effects of sleep inertia on cognition.
JAMA. 2006 Jan 11;295(2):163-4. [PMID: 16403927]

Landrigan CP, Lockley SW, Czeisler CA. Effect of intern's consecutive work hours on safety, medical education and professionalism.
Crit Care. 2005 Oct 5;9(5):528-30; author reply 528-30. Epub 2005 May 24. [PMID: 16277743]

Zeitzer JM, Khalsa SB, Boivin DB, Duffy JF, Shanahan TL, Kronauer RE, Czeisler CA. Temporal dynamics of late-night photic stimulation of the human circadian timing system.
Am J Physiol Regul Integr Comp Physiol. 2005 Sep;289(3):R839-44. Epub 2005 May 12. [PMID: 15890792]

Santhi N, Duffy JF, Horowitz TS, Czeisler CA. Scheduling of sleep/darkness affects the circadian phase of night shift workers.
Neurosci Lett. 2005 Aug 26;384(3):316-20. Erratum in: Neurosci Lett. 2005 Dec 30;390(3):187. [PMID: 15919151]

Czeisler CA, Walsh JK, Roth T, Hughes RJ, Wright KP, Kingsbury L, Arora S, Schwartz JR, Niebler GE, Dinges DF; U.S. Modafinil in Shift Work Sleep Disorder Study Group. Modafinil for excessive sleepiness associated with shift-work sleep disorder.
N Engl J Med. 2005 Aug 4;353(5):476-86. Erratum in: N Engl J Med. 2005 Sep 8;353(10):1078. [PMID: 16079371]

Rothschild JM, Landrigan CP, Cronin JW, Kaushal R, Lockley SW, Burdick E, Stone PH, Lilly CM, Katz JT, Czeisler CA, Bates DW. The Critical Care Safety Study: The incidence and nature of adverse events and serious medical errors in intensive care.
Crit Care Med. 2005 Aug;33(8):1694-700. [PMID: 16096443]

Wright KP Jr, Gronfier C, Duffy JF, Czeisler CA. Intrinsic period and light intensity determine the phase relationship between melatonin and sleep in humans.
J Biol Rhythms. 2005 Apr;20(2):168-77. [PMID: 15834113]

Barger LK, Cade BE, Ayas NT, Cronin JW, Rosner B, Speizer FE, Czeisler CA; Harvard Work Hours, Health, and Safety Group. Extended work shifts and the risk of motor vehicle crashes among interns.
N Engl J Med. 2005 Jan 13;352(2):125-34. [PMID: 15647575]

Zeitzer JM, Ayas NT, Wu AD, Czeisler CA, Brown R. Bilateral oculosympathetic paresis associated with loss of nocturnal melatonin secretion in patients with spinal cord injury.
J Spinal Cord Med. 2005;28(1):55-9. [PMID: 15832904]

Landrigan CP, Rothschild JM, Cronin JW, Kaushal R, Burdick E, Katz JT, Lilly CM, Stone PH, Lockley SW, Bates DW, Czeisler CA. Effect of reducing interns' work hours on serious medical errors in intensive care units.
N Engl J Med. 2004 Oct 28;351(18):1838-48. [PMID: 15509817]

Lockley SW, Cronin JW, Evans EE, Cade BE, Lee CJ, Landrigan CP, Rothschild JM, Katz JT, Lilly CM, Stone PH, Aeschbach D, Czeisler CA; Harvard Work Hours, Health and Safety Group. Effect of reducing interns' weekly work hours on sleep and attentional failures.
N Engl J Med. 2004 Oct 28;351(18):1829-37. [PMID: 15509816]

Gronfier C, Wright KP Jr, Kronauer RE, Jewett ME, Czeisler CA. Efficacy of a single sequence of intermittent bright light pulses for delaying circadian phase in humans.
Am J Physiol Endocrinol Metab. 2004 Jul;287(1):E174-81. Epub 2004 Mar 23. [PMID: 15039146]

Smith KA, Schoen MW, Czeisler CA. Adaptation of human pineal melatonin suppression by recent photic history.
J Clin Endocrinol Metab. 2004 Jul;89(7):3610-4. Erratum in: J Clin Endocrinol Metab. 2005 Mar;90(3):1370. [PMID: 15240654]

Barger LK, Wright KP Jr, Hughes RJ, Czeisler CA. Daily exercise facilitates phase delays of circadian melatonin rhythm in very dim light.
Am J Physiol Regul Integr Comp Physiol. 2004 Jun;286(6):R1077-84. Epub 2004 Mar 18. [PMID: 15031136]

Wyatt JK, Cajochen C, Ritz-De Cecco A, Czeisler CA, Dijk DJ. Low-dose repeated caffeine administration for circadian-phase-dependent performance degradation during extended wakefulness.
Sleep. 2004 May 1;27(3):374-81. [PMID: 15164887]

Horowitz TS, Cade BE, Wolfe JM, Czeisler CA. Searching night and day: a dissociation of effects of circadian phase and time awake on visual selective attention and vigilance.
Psychol Sci. 2003 Nov;14(6):549-57. [PMID: 14629685]

Lockley SW, Brainard GC, Czeisler CA. High sensitivity of the human circadian melatonin rhythm to resetting by short wavelength light.
J Clin Endocrinol Metab. 2003 Sep;88(9):4502-5. [PMID: 12970330]

Hull JT, Wright KP Jr, Czeisler CA. The influence of subjective alertness and motivation on human performance independent of circadian and homeostatic regulation.
J Biol Rhythms. 2003 Aug;18(4):329-38. [PMID: 12932085]

Khalsa SB, Jewett ME, Cajochen C, Czeisler CA. A phase response curve to single bright light pulses in human subjects.
J Physiol. 2003 Jun 15;549(Pt 3):945-52. Epub 2003 Apr 25. [PMID: 12717008]

Wright KP Jr, Hull JT, Czeisler CA. Relationship between alertness, performance, and body temperature in humans.
Am J Physiol Regul Integr Comp Physiol. 2002 Dec;283(6):R1370-7. Epub 2002 Aug 15. [PMID: 12388468]

Klerman EB, Shanahan TL, Brotman DJ, Rimmer DW, Emens JS, Rizzo JF 3rd, Czeisler CA. Photic resetting of the human circadian pacemaker in the absence of conscious vision.
J Biol Rhythms. 2002 Dec;17(6):548-55. [PMID: 12465888]

Wright KP Jr, Czeisler CA. Absence of circadian phase resetting in response to bright light behind the knees.
Science. 2002 Jul 26;297(5581):571. [PMID: 12142528]

Khalsa SB, Conroy DA, Duffy JF, Czeisler CA, Dijk DJ. Sleep- and circadian-dependent modulation of REM density.
J Sleep Res. 2002 Mar;11(1):53-9. [PMID: 11869427]

Duffy JF, Zeitzer JM, Rimmer DW, Klerman EB, Dijk DJ, Czeisler CA. Peak of circadian melatonin rhythm occurs later within the sleep of older subjects.
Am J Physiol Endocrinol Metab. 2002 Feb;282(2):E297-303. [PMID: 11788360]

Duffy JF, Czeisler CA. Age-related change in the relationship between circadian period, circadian phase, and diurnal preference in humans.
Neurosci Lett. 2002 Feb 1;318(3):117-20. [PMID: 11803113]

Cajochen C, Wyatt JK, Czeisler CA, Dijk DJ. Separation of circadian and wake duration-dependent modulation of EEG activation during wakefulness.
Neuroscience. 2002;114(4):1047-60. [PMID: 12379258]

Wright KP Jr, Hughes RJ, Kronauer RE, Dijk DJ, Czeisler CA. Intrinsic near-24-h pacemaker period determines limits of circadian entrainment to a weak synchronizer in humans.
Proc Natl Acad Sci U S A. 2001 Nov 20;98(24):14027-32. [PMID: 11717461]

Dijk DJ, Neri DF, Wyatt JK, Ronda JM, Riel E, Ritz-De Cecco A, Hughes RJ, Elliott AR, Prisk GK, West JB, Czeisler CA. Sleep, performance, circadian rhythms, and light-dark cycles during two space shuttle flights.
Am J Physiol Regul Integr Comp Physiol. 2001 Nov;281(5):R1647-64. [PMID: 11641138]

Horowitz TS, Cade BE, Wolfe JM, Czeisler CA. Efficacy of bright light and sleep/darkness scheduling in alleviating circadian maladaptation to night work.
Am J Physiol Endocrinol Metab. 2001 Aug;281(2):E384-91. [PMID: 11440916]

Elliott AR, Shea SA, Dijk DJ, Wyatt JK, Riel E, Neri DF, Czeisler CA, West JB, Prisk GK. Microgravity reduces sleep-disordered breathing in humans.
Am J Respir Crit Care Med. 2001 Aug 1;164(3):478-85. [PMID: 11500354]

Duffy JF, Rimmer DW, Czeisler CA. Association of intrinsic circadian period with morningness-eveningness, usual wake time, and circadian phase.
Behav Neurosci. 2001 Aug;115(4):895-9. [PMID: 11508728]

Dijk DJ, Duffy JF, Czeisler CA. Age-related increase in awakenings: impaired consolidation of nonREM sleep at all circadian phases.
Sleep. 2001 Aug 1;24(5):565-77. [PMID: 11480654]

Klerman EB, Zeitzer JM, Duffy JF, Khalsa SB, Czeisler CA. Absence of an increase in the duration of the circadian melatonin secretory episode in totally blind human subjects.
J Clin Endocrinol Metab. 2001 Jul;86(7):3166-70. [PMID: 11443183]

Klerman EB, Duffy JF, Dijk DJ, Czeisler CA. Circadian phase resetting in older people by ocular bright light exposure.
J Investig Med. 2001 Jan;49(1):30-40. [PMID: 11217145]

Khalsa SBS, Jewett ME, Duffy JF, Czeisler CA. The timing of the human circadian clock is accurately represented by the core body temperature rhythm following phase shifts to a three-cycle light stimulus near the critical zone.
J Biol Rhythms. 2000 Dec;15(6):524-30. [PMID: 11106069]

Rimmer DW, Boivin DB, Shanahan TL, Kronauer RE, Duffy JF, Czeisler CA. Dynamic resetting of the human circadian pacemaker by intermittent bright light.
Am J Physiol Regul Integr Comp Physiol. 2000 Nov;279(5):R1574-9. [PMID: 11049838]

Cajochen C, Zeitzer JM, Czeisler CA, Dijk DJ. Dose-response relationship for light intensity and ocular and electroencephalographic correlates of human alertness.
Behav Brain Res. 2000 Oct;115(1):75-83. [PMID: 10996410]

Brown EN, Choe Y, Luithardt H, Czeisler CA. A statistical model of the human core-temperature circadian rhythm.
Am J Physiol Endocrinol Metab. 2000 Sep;279(3):E669-83. [PMID: 10950837]

Zeitzer JM, Dijk DJ, Kronauer R, Brown E, Czeisler C. Sensitivity of the human circadian pacemaker to nocturnal light: melatonin phase resetting and suppression.
J Physiol. 2000 Aug 1;526 Pt 3:695-702. [PMID: 10922269]

Spengler CM, Czeisler CA, Shea SA. An endogenous circadian rhythm of respiratory control in humans.
J Physiol. 2000 Aug 1;526 Pt 3:683-94. Erratum in: Am J Respir Crit Care Med 2002 Oct 1;166(7):1005. [PMID: 10922018]

Zeitzer JM, Ayas NT, Shea SA, Brown R, Czeisler CA. Absence of detectable melatonin and preservation of cortisol and thyrotropin rhythms in tetraplegia.
J Clin Endocrinol Metab. 2000 Jun;85(6):2189-96. [PMID: 10852451]

Hilton MF, Umali MU, Czeisler CA, Wyatt JK, Shea SA. Endogenous circadian control of the human autonomic nervous system.
Comput Cardiol. 2000;27:197-200. [PMID: 14632012]

Zeitzer JM, Daniels JE, Duffy JF, Klerman EB, Shanahan TL, Dijk DJ, Czeisler CA. Do plasma melatonin concentrations decline with age?
Am J Med. 1999 Nov;107(5):432-6. [PMID: 10569297]

Wyatt JK, Ritz-De Cecco A, Czeisler CA, Dijk DJ. Circadian temperature and melatonin rhythms, sleep, and neurobehavioral function in humans living on a 20-h day.
Am J Physiol. 1999 Oct;277(4 Pt 2):R1152-63. [PMID: 10516257]

Cajochen C, Khalsa SB, Wyatt JK, Czeisler CA, Dijk DJ. EEG and ocular correlates of circadian melatonin phase and human performance decrements during sleep loss.
Am J Physiol. 1999 Sep;277(3 Pt 2):R640-9. [PMID: 10484479]

Klerman EB, Lee Y, Czeisler CA, Kronauer RE. Linear demasking techniques are unreliable for estimating the circadian phase of ambulatory temperature data.
J Biol Rhythms. 1999 Aug;14(4):260-74. Erratum in: J Biol Rhythms 1999 Oct;14(5):420. [PMID: 10447306]

Czeisler CA, Duffy JF, Shanahan TL, Brown EN, Mitchell JF, Rimmer DW, Ronda JM, Silva EJ, Allan JS, Emens JS, Dijk DJ, Kronauer RE. Stability, precision, and near-24-hour period of the human circadian pacemaker.
Science. 1999 Jun 25;284(5423):2177-81. [PMID: 10381883]

Shanahan TL, Kronauer RE, Duffy JF, Williams GH, Czeisler CA. Melatonin rhythm observed throughout a three-cycle bright-light stimulus designed to reset the human circadian pacemaker.
J Biol Rhythms. 1999 Jun;14(3):237-53. [PMID: 10452336]

Kelly TL, Neri DF, Grill JT, Ryman D, Hunt PD, Dijk DJ, Shanahan TL, Czeisler CA. Nonentrained circadian rhythms of melatonin in submariners scheduled to an 18-hour day.
J Biol Rhythms. 1999 Jun;14(3):190-6. [PMID: 10452330]

Dijk DJ, Duffy JF, Riel E, Shanahan TL, Czeisler CA. Ageing and the circadian and homeostatic regulation of human sleep during forced desynchrony of rest, melatonin and temperature rhythms.
J Physiol. 1999 Apr 15;516 ( Pt 2):611-27. [PMID: 10087357]

Duffy JF, Dijk DJ, Hall EF, Czeisler CA. Relationship of endogenous circadian melatonin and temperature rhythms to self-reported preference for morning or evening activity in young and older people.
J Investig Med. 1999 Mar;47(3):141-50. [PMID: 10198570]

Jewett ME, Wyatt JK, Ritz-De Cecco A, Khalsa SB, Dijk DJ, Czeisler CA. Time course of sleep inertia dissipation in human performance and alertness.
J Sleep Res. 1999 Mar;8(1):1-8. [PMID: 10188130]

Wei HG, Riel E, Czeisler CA, Dijk DJ. Attenuated amplitude of circadian and sleep-dependent modulation of electroencephalographic sleep spindle characteristics in elderly human subjects.
Neurosci Lett. 1999 Jan 22;260(1):29-32. [PMID: 10027692]

Duffy JF, Dijk DJ, Klerman EB, Czeisler CA. Later endogenous circadian temperature nadir relative to an earlier wake time in older people.
Am J Physiol. 1998 Nov;275(5 Pt 2):R1478-87. [PMID: 9791064]

Klerman EB, Rimmer DW, Dijk DJ, Kronauer RE, Rizzo JF 3rd, Czeisler CA. Nonphotic entrainment of the human circadian pacemaker.
Am J Physiol. 1998 Apr;274(4 Pt 2):R991-6. [PMID: 9575961]

Boivin DB, Czeisler CA. Resetting of circadian melatonin and cortisol rhythms in humans by ordinary room light. Neuroreport. 1998 Mar 30;9(5):779-82. [PMID: 9579664]

Dijk DJ, Shanahan TL, Duffy JF, Ronda JM, Czeisler CA. Variation of electroencephalographic activity during non-rapid eye movement and rapid eye movement sleep with phase of circadian melatonin rhythm in humans.
J Physiol. 1997 Dec 15;505 ( Pt 3):851-8. [PMID: 9457658]

Jewett ME, Rimmer DW, Duffy JF, Klerman EB, Kronauer RE, Czeisler CA. Human circadian pacemaker is sensitive to light throughout subjective day without evidence of transients.
Am J Physiol. 1997 Nov;273(5 Pt 2):R1800-9. [PMID: 9374826]

Zeitzer JM, Kronauer RE, Czeisler CA. Photopic transduction implicated in human circadian entrainment.
Neurosci Lett. 1997 Sep 5;232(3):135-8. [PMID: 9310298]

Brown EN, Choe Y, Shanahan TL, Czeisler CA. A mathematical model of diurnal variations in human plasma melatonin levels.
Am J Physiol. 1997 Mar;272(3 Pt 1):E506-16. [PMID: 9124558]

Boivin DB, Czeisler CA, Dijk DJ, Duffy JF, Folkard S, Minors DS, Totterdell P, Waterhouse JM. Complex interaction of the sleep-wake cycle and circadian phase modulates mood in healthy subjects.
Arch Gen Psychiatry. 1997 Feb;54(2):145-52. [PMID: 9040282]

el-Hajj Fuleihan G, Klerman EB, Brown EN, Choe Y, Brown EM, Czeisler CA. The parathyroid hormone circadian rhythm is truly endogenous--a general clinical research center study.
J Clin Endocrinol Metab. 1997 Jan;82(1):281-6. [PMID: 8989274]

Richardson GS, Wyatt JK, Sullivan JP, Orav EJ, Ward AE, Wolf MA, Czeisler CA. Objective assessment of sleep and alertness in medical house staff and the impact of protected time for sleep.
Sleep. 1996 Nov;19(9):718-26. [PMID: 9122559]

Duffy JF, Kronauer RE, Czeisler CA. Phase-shifting human circadian rhythms: influence of sleep timing, social contact and light exposure.
J Physiol. 1996 Aug 15;495 ( Pt 1):289-97. [PMID: 8866371]

Waldstreicher J, Duffy JF, Brown EN, Rogacz S, Allan JS, Czeisler CA. Gender differences in the temporal organization of proclactin (PRL) secretion: evidence for a sleep-independent circadian rhythm of circulating PRL levels- a clinical research center study.
J Clin Endocrinol Metab. 1996 Apr;81(4):1483-7. [PMID: 8636355]

Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Dose-response relationships for resetting of human circadian clock by light.
Nature. 1996 Feb 8;379(6565):540-2. [PMID: 8596632]

Klerman EB, Dijk DJ, Kronauer RE, Czeisler CA. Simulations of light effects on the human circadian pacemaker: implications for assessment of intrinsic period.
Am J Physiol. 1996 Jan;270(1 Pt 2):R271-82. [PMID: 8769811]

Dijk DJ, Czeisler CA. Contribution of the circadian pacemaker and the sleep homeostat to sleep propensity, sleep structure, electroencephalographic slow waves, and sleep spindle activity in humans.
J Neurosci. 1995 May;15(5 Pt 1):3526-38. [PMID: 7751928]

Czeisler CA, Shanahan TL, Klerman EB, Martens H, Brotman DJ, Emens JS, Klein T, Rizzo JF 3rd. Suppression of melatonin secretion in some blind patients by exposure to bright light.
N Engl J Med. 1995 Jan 5;332(1):6-11. [PMID: 7990870]

Budnick LD, Lerman SE, Baker TL, Jones H, Czeisler CA. Sleep and alertness in a 12-hour rotating shift work environment.
J Occup Med. 1994 Dec;36(12):1295-300. [PMID: 7884570]

Allan JS, Czeisler CA. Persistence of the circadian thyrotropin rhythm under constant conditions and after light-induced shifts of circadian phase.
J Clin Endocrinol Metab. 1994 Aug;79(2):508-12. [PMID: 8045970]

Dijk DJ, Czeisler CA. Paradoxical timing of the circadian rhythm of sleep propensity serves to consolidate sleep and wakefulness in humans.
Neurosci Lett. 1994 Jan 17;166(1):63-8. [PMID: 8190360]

Boivin DB, Duffy JF, Kronauer RE, Czeisler CA. Sensitivity of the human circadian pacemaker to moderately bright light.
J Biol Rhythms. 1994 Winter;9(3-4):315-31. [PMID: 7772798]

Jewett ME, Kronauer RE, Czeisler CA. Phase-amplitude resetting of the human circadian pacemaker via bright light: a further analysis.
J Biol Rhythms. 1994 Winter;9(3-4):295-314. [PMID: 7772797]

Dijk DJ, Hayes B, Czeisler CA. Dynamics of electroencephalographic sleep spindles and slow wave activity in men: effect of sleep deprivation.
Brain Res. 1993 Oct 29;626(1-2):190-9. [PMID: 8281430]

Dijk DJ, Czeisler CA. Body temperature is elevated during the rebound of slow-wave sleep following 40-h of sleep deprivation on a constant routine.
J Sleep Res. 1993 Sep;2(3):117-120. [PMID: 10607081]

Klein T, Martens H, Dijk DJ, Kronauer RE, Seely EW, Czeisler CA. Circadian sleep regulation in the absence of light perception: chronic non-24-hour circadian rhythm sleep disorder in a blind man with a regular 24-hour sleep-wake schedule.
Sleep. 1993 Jun;16(4):333-43. [PMID: 8341894]

Czeisler CA, Dumont M, Duffy JF, Steinberg JD, Richardson GS, Brown EN, Sánchez R, Ríos CD, Ronda JM. Association of sleep-wake habits in older people with changes in output of circadian pacemaker.
Lancet. 1992 Oct 17;340(8825):933-6. [PMID: 1357348]

Brown EN, Czeisler CA. The statistical analysis of circadian phase and amplitude in constant-routine core-temperature data.
J Biol Rhythms. 1992 Fall;7(3):177-202. [PMID: 1421473]

Gold DR, Rogacz S, Bock N, Tosteson TD, Baum TM, Speizer FE, Czeisler CA. Rotating shift work, sleep, and accidents related to sleepiness in hospital nurses.
Am J Public Health. 1992 Jul;82(7):1011-4. [PMID: 1609900]

Dijk DJ, Duffy JF, Czeisler CA. Circadian and sleep/wake dependent aspects of subjective alertness and cognitive performance.
J Sleep Res. 1992 Jun;1(2):112-7. [PMID: 10607036]

Johnson MP, Duffy JF, Dijk DJ, Ronda JM, Dyal CM, Czeisler CA. Short-term memory, alertness and performance: a reappraisal of their relationship to body temperature.
J Sleep Res. 1992 Mar;1(1):24-9. [PMID: 10607021]

Shanahan TL, Czeisler CA. Light exposure induces equivalent phase shifts of the endogenous circadian rhythms of circulating plasma melatonin and core body temperature in men.
J Clin Endocrinol Metab. 1991 Aug;73(2):227-35. [PMID: 1856258]

Jewett ME, Kronauer RE, Czeisler CA. Light-induced suppression of endogenous circadian amplitude in humans.
Nature. 1991 Mar 7;350(6313):59-62. [PMID: 2002845]

Czeisler CA, Johnson MP, Duffy JF, Brown EN, Ronda JM, Kronauer RE. Exposure to bright light and darkness to treat physiologic maladaptation to night work.
N Engl J Med. 1990 May 3;322(18):1253-9. [PMID: 2325721]

Czeisler CA, Kronauer RE, Allan JS, Duffy JF, Jewett ME, Brown EN, Ronda JM. Bright light induction of strong (type 0) resetting of the human circadian pacemaker.
Science. 1989 Jun 16;244(4910):1328-33. [PMID: 2734611]

Brezinski DA, Tofler GH, Muller JE, Pohjola-Sintonen S, Willich SN, Schafer AI, Czeisler CA, Williams GH. Morning increase in platelet aggregability. Association with assumption of the upright posture.
Circulation. 1988 Jul;78(1):35-40. [PMID: 3289790]

Strogatz SH, Kronauer RE, Czeisler CA. Circadian pacemaker interferes with sleep onset at specific times each day: role in insomnia.
Am J Physiol. 1987 Jul;253(1 Pt 2):R172-8. [PMID: 3605382]

Tofler GH, Brezinski D, Schafer AI, Czeisler CA, Rutherford JD, Willich SN, Gleason RE, Williams GH, Muller JE. Concurrent morning increase in platelet aggregability and the risk of myocardial infarction and sudden cardiac death.
N Engl J Med. 1987 Jun 11;316(24):1514-8. [PMID: 3587281]

Gordon NP, Cleary PD, Parker CE, Czeisler CA. The prevalence and health impact of shiftwork.
Am J Public Health. 1986 Oct;76(10):1225-8. [PMID: 3752325]

Czeisler CA, Allan JS, Strogatz SH, Ronda JM, Sánchez R, Ríos CD, FreitagWO, Richardson GS, Kronauer RE. Bright light resets the human circadian pacemaker independent of the timing of the sleep-wake cycle.
Science. 1986 Aug 8;233(4764):667-71. [PMID: 3726555]

Strogatz SH, Kronauer RE, Czeisler CA. Circadian regulation dominates homeostatic control of sleep length and prior wake length in humans.
Sleep. 1986 Jun;9(2):353-64. [PMID: 3505735]

Moline ML, Monk TH, Wagner DR, Pollak CP, Kream J, Fookson JE, Weitzman ED, Czeisler CA. Human growth hormone release is decreased during sleep in temporal isolation (free-running).
Chronobiologia. 1986 Jan-Mar;13(1):13-9. [PMID: 3720426]

Muller JE, Stone PH, Turi ZG, Rutherford JD, Czeisler CA, Parker C, Poole WK, Passamani E, Roberts R, Robertson T, Sobel BE, Willerson JT, Braunwald E and the MILLIS study group. Circadian variation in the frequency of onset of acute myocardial infarction.
N Engl J Med. 1985 Nov 21;313(21):1315-22. [PMID: 2865677]

Richardson GS, Moore-Ede MC, Czeisler CA, Dement WC. Circadian rhythms of sleep and wakefulness in mice: analysis using long-term automated recording of sleep.
Am J Physiol. 1985 Mar;248(3 Pt 2):R320-30. [PMID: 3838419]

Gander PH, Kronauer RE, Czeisler CA, Moore-Ede MC. Modeling the action of zeitgebers on the human circadian system: comparisons of simulations and data.
Am J Physiol. 1984 Sep;247(3 Pt 2):R427-44. [PMID: 6476143]

Gander PH, Kronauer RE, Czeisler CA, Moore-Ede MC. Simulating the action of zeitgebers on a coupled two-oscillator model of the human circadian system.
Am J Physiol. 1984 Sep;247(3 Pt 2):R418-26. [PMID: 6476142]

Weitzman ED, Zimmerman JC, Czeisler CA, Ronda J. Cortisol secretion is inhibited during sleep in normal man.
J Clin Endocrinol Metab. 1983 Feb;56(2):352-8. [PMID: 6822642]

Czeisler CA, Moore-Ede MC, Coleman RH. Rotating shift work schedules that disrupt sleep are improved by applying circadian principles.
Science. 1982 Jul 30;217(4558):460-3. [PMID: 7089576]

Kronauer RE, Czeisler CA, Pilato SF, Moore-Ede MC, Weitzman ED. Mathematical model of the human circadian system with two interacting oscillators.
Am J Physiol. 1982 Jan;242(1):R3-17. [PMID: 7058927]

Weitzman ED, Moline ML, Czeisler CA, Zimmerman JC. Chronobiology of aging: temperature, sleep-wake rhythms and entrainment.
Neurobiol Aging. 1982 Winter;3(4):299-309. [PMID: 7170047]

Bernstein IL, Zimmerman JC, Czeisler CA, Weitzman ED. Meal patterns in "free-running" humans.
Physiol Behav. 1981 Oct;27(4):621-3. [PMID: 7323164]

Czeisler CA, Richardson GS, Zimmerman JC, Moore-Ede MC, Weitzman ED. Entrainment of human circadian rhythms by light-dark cycles: a reassessment.
Photochem Photobiol. 1981 Aug;34(2):239-47. [PMID: 7267730]

Weitzman ED, Czeisler CA, Coleman RM, Spielman AJ, Zimmerman JC, Dement W, Richardson G, Pollak CP. Delayed sleep phase syndrome. A chronobiological disorder with sleep-onset insomnia.
Arch Gen Psychiatry. 1981 Jul;38(7):737-46. [PMID: 7247637]

Czeisler CA, Richardson GS, Coleman RM, Zimmerman JC, Moore-Ede MC, Dement WC, Weitzman ED. Chronotherapy: resetting the circadian clocks of patients with delayed sleep phase insomnia.
Sleep. 1981;4(1):1-21. [PMID: 7232967]

Czeisler CA, Weitzman E, Moore-Ede MC, Zimmerman JC, Knauer RS. Human sleep: its duration and organization depend on its circadian phase.
Science. 1980 Dec 12;210(4475):1264-7. [PMID: 7434029]

Zimmerman JC, Czeisler CA, Laxminarayan S, Knauer RS, Weitzman ED. REM density is dissociated from REM sleep timing during free-running sleep episodes.
Sleep. 1980;2(4):409-15. [PMID: 7403741]

Weitzman ED, Czeisler CA, Zimmerman JC, Ronda JM. Timing of REM and stages 3 + 4 sleep during temporal isolation in man.
Sleep. 1980;2(4):391-407. [PMID: 7403740]

Czeisler CA, Zimmerman JC, Ronda JM, Moore-Ede MC, Weitzman ED. Timing of REM sleep is coupled to the circadian rhythm of body temperature in man.  
Sleep. 1980;2(3):329-46. [PMID: 7403736]

Lydic R, Schoene WC, Czeisler CA, Moore-Ede MC. Suprachiasmatic region of the human hypothalamus: homolog to the primate circadian pacemaker?
Sleep. 1980;2(3):355-61. [PMID: 6773133]

Kokkoris CP, Weitzman ED, Pollak CP, Spielman AJ, Czeisler CA, Bradlow H. Long-term ambulatory temperature monitoring in a subject with a hypernychthemeral sleep--wake cycle disturbance.
Sleep. 1978 Winter;1(2):177-90. [PMID: 756061]

Czeisler CA, Ede MC, Regestein QR, Kisch ES, Fang VS, Ehrlich EN. Episodic 24-hour cortisol secretory patterns in patients awaiting elective cardiac surgery.
J Clin Endocrinol Metab. 1976 Feb;42(2):273-83. [PMID: 1262431]

Book Chapters

Czeisler, CA, Buxton OM.  The human circadian timing system and sleep-wake regulation.
In: M Kryger, T Roth, W Dement eds., Principles and Practices of Sleep Medicine. 2010; 402-19.

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