Faculty Profile

Medical Chronobiology Program, Division of Sleep Medicine, Brigham and Women's Hospital

The severity of many diseases varies across the 24-hour period. For example, heart attacks occur most frequently in the morning a few hours after waking up, temporal lobe epileptic seizures of the brain's temporal lobe usually occur in the late afternoon or early evening, and asthma is generally worst at night. The goal of the Medical Chronobiology Program at Brigham and Women's Hospital is to understand the biological basis behind these time-variant changes in disease severity. We aim to determine whether or not these changes are caused by the body clock (the endogenous circadian pacemaker) or attributable to behaviors that occur on a regular daily basis, including the sleep/wake cycle. Understanding the biological basis of these changes across the day and night may provide an insight into the underlying cause of the disease and could lead to better therapy (e.g. appropriately timed medication to target specific phases of the body clock or to coincide with specific behaviors that cause vulnerability, such as exercise).

Steven A. Shea, PhD; Charles A. Czeisler, PhD, MD

NIH R01 (National Heart, Lung & Blood Institute); PI: S.A. Shea
"Circadian and behavioral factors of cardiovascular risk"

NIH RO1 (National Heart, Lung & Blood Institute); PI: C.A. Czeisler
"Adaptation of circadian responses to light treatment"

NIH R21 (National Center for Complementary and Alternative Medicine);PI: F.A.J.L. Scheer
"Melatonin supplementation in hypertensive patients treated with beta-blockers"

Pickwick Fellowship (National Sleep Foundation); PI: F.A.J.L. Scheer
"Restoration of sleep quality in hypertensive patients"

American Sleep Medicine Foundation; PI: F.A.J.L. Scheer
"Restoration of sleep in heart failure patients"

2003: Teaching Fellow, MCB 186, Circadian Biology: From Cellular Oscillators to Sleep Regulation, Harvard University

2004-2006: Teaching Fellow, BIOL E-180, The Physiology of Sleep, Harvard Extension School

Recent Awards
Awards and Honors:
2005    Pickwick Postdoctoral Fellowship, National Sleep Foundation (2005-2007)
2005    Young Investigator Neurology Section Award, American Academy of Sleep Medicine
2006    Alliance Chronosleep Award, European Sleep Research Society
2006    Finalist Helgi Kristbjarnarson's Award, European Sleep Research Society
2007    Young Investigator Award, American Academy of Sleep Medicine for abstract                         “Desynchrony between sleep-wake cycle and circadian cycle leads to suppressed                 plasma leptin; potential relevance for shift workers”


Related Websites
Medical Chronobiology Program
Curriculum Vitae

Hu K, Scheer FAJL, Buijs RM, Shea SA. The endogenous circadian pacemaker imparts a scale-invariant pattern of heart rate fluctuations across time scales spanning minutes to 24 hours. J Biol Rhythms, in press.

Hu K, Scheer FAJL, Ivanov PCh, Buijs RM, Shea SA. The suprachiasmatic nucleus functions beyond circadian rhythm generation.
Neuroscience. 2007;149(3):508-517 [PMID: 17920204]

Scheer FAJL, Wright Jr. KP, Kronauer RE, Czeisler CA. Plasticity of the Intrinsic Period of the Human Circadian Timing System.
PLoS ONE. 2007;2(1):e721. [PMID: 17684566]

Scheer FA, Stone PH, Shea SA. Decreased sleep in heart failure: are medications to blame?
Arch Intern Med. 2007 May 28;167(10):1098-9; author reply 1099-100. No abstract
available. [PMID: 17533214]

Kalsbeek A, Palm IF, La Fleur SE, Scheer FA, Perreau-Lenz S, Ruiter M, Kreier
F, Cailotto C, Buijs RM. SCN outputs and the hypothalamic balance of life.
J Biol Rhythms. 2006 Dec;21(6):458-69. Review. [PMID: 17107936]

Kalsbeek A, Palm IF, La Fleur SE, Scheer FA, Perreau-Lenz S, Ruiter M, Kreier F,
Cailotto C, Buijs RM.  SCN outputs and the hypothalamic balance of life. 
J Biol Rhythms. 2006 Dec;21(6):458-69. [PMID: 17107936]

Buijs RM, Scheer FA, Kreier F, Yi C, Bos N, Goncharuk VD, Kalsbeek A. Chapter 20: Organization of circadian functions: interaction with the body.
Prog Brain Res. 2006;153:341-60.

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. Potential use of melatonin as adjunct antihypertensive therapy.
Am J Hypertens. 2005 Dec;18(12 Pt 1):1619-20. No abstract available. [PMID: 16364835]

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] 

Scheer FA, Pirovano C, Van Someren EJ, Buijs RM. Environmental light and suprachiasmatic nucleus interact in the regulation of body temperature.
Neuroscience. 2005;132(2):465-77. [PMID: 15802197]

Scheer FA, Czeisler CA. Melatonin, sleep, and circadian rhythms.
Sleep Med Rev. 2005 Feb;9(1):5-9. Review. No abstract available. [PMID: 15649734]

Scheer FA, Van Doornen LJ, Buijs RM. Light and diurnal cycle affect autonomic cardiac balance in human; possible role for the biological clock.
Auton Neurosci. 2004 Jan 30;110(1):44-8. [PMID: 14766324]

Scheer FA, Van Montfrans GA, van Someren EJ, Mairuhu G, Buijs RM. Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension.
Hypertension. 2004 Feb;43(2):192-7. Epub 2004 Jan 19. [PMID: 14732734] 

Scheer FA, Kalsbeek A, Buijs RM. Cardiovascular control by the suprachiasmatic nucleus: neural and neuroendocrine mechanisms in human and rat.
Biol Chem. 2003 May;384(5):697-709. Review. [PMID: 12817466]

Scheer FA, Van Paassen B, Van Montfrans GA, Fliers E, Van Someren EJ, Van Heerikhuize JJ, Buijs RM. Human basal cortisol levels are increased in hospital compared to home setting.
Neurosci Lett. 2002 Nov 22;333(2):79-82. [PMID: 12419485]

Scheer FA, Ter Horst GJ, van Der Vliet J, Buijs RM. Physiological and anatomic evidence for regulation of the heart by suprachiasmatic nucleus in rats.
Am J Physiol Heart Circ Physiol. 2001 Mar;280(3):H1391-9. [PMID: 11179089]

Scheer FA, Buijs RM. Light affects morning salivary cortisol in humans.
J Clin Endocrinol Metab. 1999 Sep;84(9):3395-8. [PMID: 10487717] 

Scheer FA, van Doornen LJ, Buijs RM. Light and diurnal cycle affect human heart rate: possible role for the circadian pacemaker.
J Biol Rhythms. 1999 Jun;14(3):202-12. [PMID: 10452332]