Research interests

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.

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).

Publications

• Rosenwasser, A.M. Entrainment of circadian rhythms by light. In L.R. Squire, ed., Encyclopedia of Neuroscience, Volume 3, Oxford: Academic Press, 2009, pp. 1125-1132.

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• Rosenwasser, A.M. Functional neuroanatomy of sleep and circadian rhythms. Brain Research Reviews, 61, 281-306, 2009. DOI: 10.1016/j.brainresrev.2009.08.001.

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• Seggio, J.A., Fixaris, J.D., Reed, J.D., Logan, R.W. and Rosenwasser, A.M. Chronic ethanol intake alters circadian phase shifting and free-running period in mice. Journal of Biological Rhythms, 24, 304-312, 2009. DOI: 10.1177/0748730409338449

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• 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, 87, 297-305, 2007.

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• 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, 31, 1699-1706, 2007.

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• 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.

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• 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.

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• 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.

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• 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.

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• 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.

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