Faculty Profile

Sean W. Cain, PhD

Lecturer on Medicine, Harvard Medical School
Associate Neuroscientist, Division of Sleep and Circadian Disorders, Departments of Medicine and Neurology, Brigham and Women's Hospital

See publications


BWH Division of Sleep Medicine, Brigham and Women's Hospital, Harvard Medical School
221 Longwood Avenue
Boston, MA 02115

Inter-office Mail Address


Society Memberships

Sleep Research Society
American Sleep Medicine Foundation
Society for Research on Biological Rhythms
Society For Neuroscience

Research Interests

My research interests include sex differences in circadian rhythms and sleep, rhythms in cognitive performance, the neurobiology of nonphotic input to the biological clock, and the effect of aging on circadian function and cognition.

During my PhD work at the University of Toronto, I discovered that optimal learning performance depends on the matching of time of testing with time that learning occurred. Time of learning appears to be a context feature that is registered during conditioning, even though time itself may not an explicit discriminative cue. Animals in general, seem to be predisposed to anticipate the recurrence of important events at circa-24 hour intervals.

Currently, I am examining circadian rhythms and sleep in human subjects. My primary focus is the examination of the relative influences of the circadian clock and sleep-wake homeotstat on cognitive function. This work involves examining how acute and chronic sleep loss affects different aspects of cognition across the 24-hour biological day. My work also focuses on sex differences in circadian rhythms and sleep. I have recently found that the habitual sleep of women is advanced, relative to men. This advanced timing may make women more vulnerable sleep disruption and insomnia.


Research Funding

AMSF, PI: Sean W. Cain,
Evaluation of the circadian time of sleep in women with and without insomnia.
Role: PI

Selected Publications

Lee JH, Wang W, Silva EJ, Chang AM, Scheuermaier KD, Cain SW, Duffy JF. Neurobehavioral performance in young adults living on a 28-h day for 6 weeks.
Sleep. 2009 Jul 1;32(7):905-13. [PMID: 19639753]

Cain SW, Ralph MR. Circadian modulation of conditioned place avoidance in hamsters does not require the suprachiasmatic nucleus.
Neurobiol Learn Mem. 2009  Jan;91(1):81-4. Epub 2008 Nov 28. [PMID: 19013252]

Cain SW, McDonald RJ, Ralph MR. Time stamp in conditioned place avoidance can be set to different circadian phases.
Neurobiol Learn Mem. 2008 May;89(4):591-4.  Epub 2007 Oct 1. [PMID: 17905603]

Cain SW, Rimmer DW, Duffy JF, Czeisler CA. Exercise distributed across day and night does not alter circadian period in humans.
J Biol Rhythms. 2007 Dec;22(6):534-41. [PMID: 18057328]

Cain SW, Verwey M, Szybowska M, Ralph MR, Yeomans JS. Carbachol injections into the intergeniculate leaflet induce nonphotic phase shifts.
Brain Res. 2007 Oct 26;1177:59-65. Epub 2007 Aug 9. [PMID: 17920045]

Cain SW, Verwey M, Hood S, Leknickas P, Karatsoreos I, Yeomans JS, Ralph MR. Reward and aversive stimuli produce similar nonphotic phase shifts.
Behav Neurosci. 2004 Feb;118(1):131-7. [PMID: 14979789]

Cain SW, Karatsoreos I, Gautam N, Konar Y, Funk D, McDonald RJ, Ralph MR. Blunted cortisol rhythm is associated with learning impairment in aged hamsters.
Physiol Behav. 2004 Sep 15;82(2-3):339-44. [PMID: 15276797]

Cain SW, Chou T, Ralph MR. Circadian modulation of performance on an aversion-based place learning task in hamsters.
Behav Brain Res. 2004 Apr 2;150(1-2):201-5. [PMID: 15033293]

Cain SW, Ko CH, Chalmers JA, Ralph MR. Time of day modulation of conditioned place preference in rats depends on the strain of rat used.
Neurobiol Learn Mem. 2004 May;81(3):217-20.  [PMID: 15082023]

Cheng HY, Obrietan K, Cain SW, Lee BY, Agostino PV, Joza NA, Harrington ME, Ralph MR, Penninger JM. Dexras1 potentiates photic and suppresses nonphotic responses of the circadian clock.
Neuron. 2004 Sep 2;43(5):715-28. [PMID: 15339652]

Kippin TE, Cain SW, Masum Z, Ralph MR. Neural stem cells show bidirectional experience-dependent plasticity in the perinatal mammalian brain.
J Neurosci. 2004 Mar 17;24(11):2832-6. [PMID: 15028777]

Kippin TE, Cain SW, Pfaus JG. Estrous odors and sexually conditioned neutral
odors activate separate neural pathways in the male rat.
2003;117(4):971-9. [PMID: 12654349]

Shin DS, Ghai H, Cain SW, Buck LT. Gap junctions do not underlie changes in
whole-cell conductance in anoxic turtle brain.
Comp Biochem Physiol A Mol Integr Physiol. 2003 Jan;134(1):181-94. [PMID: 12507621]

Coward DJ, Cain SW & Ralph MR. A circadian rhythm in mice that is unaffected by the period mutation at clock.
Biological Rhythm Research 2001; 32(2), 233-242.

Amir S, Cain S, Sullivan J, Robinson B, Stewart J. In rats, odor-induced Fos
in the olfactory pathways depends on the phase of the circadian clock.
Neurosci Lett. 1999 Sep 17;272(3):175-8. [PMID: 10505609]

Flores C, Salmaso N, Cain S, Rodaros D, Stewart J. Ovariectomy of adult rats
leads to increased expression of astrocytic basic fibroblast growth factor in the
ventral tegmental area and in dopaminergic projection regions of the entorhinal
and prefrontal cortex.
J Neurosci. 1999 Oct 1;19(19):8665-73. [PMID:10493767]

Amir S, Cain S, Sullivan J, Robinson B, Stewart J. Olfactory stimulation
enhances light-induced phase shifts in free-running activity rhythms and Fos
expression in the suprachiasmatic nucleus.
Neuroscience. 1999;92(4):1165-70. [PMID: 10426475]

Site Map | Contact Us | © 2017 by the President and Fellows of Harvard College