Faculty
Research
in my laboratory focuses on the analysis of behavioral circadian
rhythms in rodents.
What are circadian rhythms?
Circadian rhythms are endogenous biological cycles with approximately
24-hour periods that influencing physiological and behavioral
processes ranging from gene expression and metabolism to mood
and cognition. In complex animals, circadian rhythms are controlled
by a hierarchically-organized, multi-oscillatory circadian timing
system comprised of a circadian "pacemaker", localized
in the suprachiasmatic nucleus (SCN) of the hypothalamus, as
well as a large number of "secondary" circadian
oscillators, located elsewhere in the brain and in glands and
organs throughout the body. This distributed circadian system
is normally synchronized ("entrained") by periodic
factors in the environment, including daily cycles of light
and darkness, temperature, and food availability. Recent research
has indicated that disruption of normal circadian timing contributes
to sleep disorders, depression, jet-lag and shift-work related
health problems, and cancer. Thus, the study of circadian rhythms
is critical to understanding normative psychobiological function,
to the improvement of public health, and to the development
of better treatments for various medical conditions.
What are we currently working on?
For the last few years, my laboratory has been exploring relationships
between circadian rhythms and alcohol intake in various animal
models, including rats, mice, and hamsters, in order to better
understand the disruptions in sleep and circadian rhythms that
are commonly associated with alcohol abuse in human populations.
In these studies, we are examining the effects of chronic and
acute alcohol treatments on circadian rhythms, as well as the
reciprocal effects of circadian rhythm disruption on voluntary
alcohol intake. In addition, our work takes advantage of the
availability of special rat and mouse lines with well-characterized
genetic predispositions to consume (or avoid) alcohol. To date,
we have found that chronic alcohol intake alters fundamental
properties of the circadian pacemaker, including its "free-running"
period and its control by light-dark cycles, and that exposure
to a simulated "jet-lag" lighting regimen modulates
alcohol intake. We hope that this work will eventually lead
to the development of improved circadian-based strategies for
the management or even prevention of alcohol related disorders.
This work has been supported by the National Institute for Alcohol
Abuse and Alcoholism (NIAAA), and by the NIAAA-funded Integrative
Neuroscience Initiative on Alcoholism (INIA).
Recent
Publications:
Seggio,
J. A., Logan, R. W. and Rosenwasser, A. M. Chronic ethanol intake
modulates photic and non-photic circadian phase shifting in
the Syrian hamster. Pharmacology Biochemistry and Behavior,
in press.
Clark, J. W., Fixaris, M. C., Belanger, G. V. and Rosenwasser,
A. M. Repeated light-dark phase shifts modulate voluntary ethanol
intake in male and female high alcohol-drinking (HAD1) rats.
Alcoholism: Clinical and Experimental Research, in press.
Rosenwasser, A. M. Entrainment of circadian rhythms by light.
In L. Squire et al., Eds., The New Encyclopedia of Neuroscience,
in press.
Rosenwasser, A. M. and Turek, F. W. Physiology of the mammalian
circadian system. In M. H. Kryger, T. Roth and W. C. Dement,
eds., Principles and Practice of Sleep Medicine, Fourth Edition,
Elsevier-Saunders, 2005, pp. 351-362.
Rosenwasser, A. M., Logan, R. W. and Fecteau, M. E. Chronic
ethanol intake alters circadian period-responses to brief light
pulses in rats. Chronobiology International, 22, 225-234, 2005.
Rosenwasser, A. M., Fecteau, M. E. and Logan, R. W. Effects
of ethanol intake and ethanol withdrawal on free-running circadian
activity rhythms in rats. Physiology and Behavior, 84, 537-542,
2005.
Spanagel, R., Rosenwasser, A. M., Schumann, G., and Sarkar,
D. K. Alcohol consumption and the body’s biological clock.
Alcoholism: Clinical and Experimental Research, 29, 1550-1557,
2005.
Rosenwasser, A. M., Fecteau, M. E., Logan, R. W., Reed. J. D.,
Cotter, S. J. N. and Seggio, J. A. Circadian activity rhythms
in selectively bred ethanol-preferring and nonpreferring rats.
Alcohol, 36, 69-81, 2005.
Boulos, Z. and Rosenwasser, A. M. A chronobiological perspective
on allostasis and its application to shift work. In J. Schulkin,
ed., Allostasis, Homeostasis, and the Costs of Physiological
Regulation, Cambridge, 2004, pp. 228-301.
Rosenwasser, A. M. Neurobiology of the mammalian circadian system:
oscillators, pacemakers, and pathways. In S. J. Fluharty and
H. J. Grill, eds., Progress in Psychobiology and Physiological
Psychology v.18, Elsevier Academic Press, 2003, pp.1-38.
Rosenwasser, A. M. and Dwyer, S. M. Phase shifting the hamster
circadian clock by 15 minute dark pulses. Journal of Biological
Rhythms, 17, 238-247, 2002.
Rosenwasser, A. M. and Dwyer, S. M. Circadian phase shifting:
relationships between photic and non-photic phase-response curves.
Physiology and Behavior, 73, 175-183, 2001.
Rosenwasser, A. M. Alcohol, antidepressants, and circadian rhythms:
human and animal models. Alcohol Research and Health, 25, 126-135,
2001.
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