Email: f.davis@neu.edu

Phone: 617.373.4039
Fax: 617.373.3724

Location: 443 Richards Hall
Mail: NU/Biology
         134 Mugar Life Sciences
         360 Huntington Avenue
         Boston, MA 02115 USA

Lab Web Site

Research Description

My laboratory is interested in the neurobiology and development of vertebrate circadian rhythms. Biological activity from gene regulation to behavior is regulated by endogenously generated 24-hour oscillations. These circadian oscillations are normally synchronized to the environment by a process of entrainment which insures that the rhythms have adaptive relationships to daily rhythmicity in the environment. Structures that generate circadian oscillations have been identified within the nervous systems of animals, and are referred to as circadian pacemakers. In mammals, a circadian pacemaker has been localized to the suprachiasmatic nucleus (SCN), a group of cells at the base of the hypothalamus where the optic nerves enter the brain. The cells within the SCN appear to be specialized to generate circadian oscillations, to receive information about environmental cycles, and to regulate a variety of functions within the animal.

We are studying the development of the mammalian circadian pacemaker with the ultimate goal of understanding how a specific neural function, the generation and entrainment of circadian oscillations, is related to the organization of the nervous system. By studying the development of circadian rhythms and the development of the SCN we hope to identify the stages of neural development that are critical for the initiation of pacemaker function. The current focus of the laboratory is on the prenatal entrainment of circadian oscillations in hamsters. Previous work has shown that the fetal pacemaker (the SCN) is entrained by an unidentified signal from the mother. We are working to identify this signal and to determine when and how it acts on the developing pacemaker to cause entrainment. We use a variety of techniques to study the development of circadian rhythms, including the recording of behavioral rhythms, the use of neuroanatomical techniques such as in situ hybridization and immunohistochemistry, and the transplantation of developing neural tissue.

Selected Publications

Li, X., J. Gilbert, and F.C. Davis. Disruption of masking by hypothalamic lesions in Syrian hamsters. J. Comp. Physiol. A 191:23-30, 2005.

Snodgrass-Belt, P., J. Gilbert and F. C. Davis. Central Administration of Transforming Growth Factor-Alpha and Neuregulin-1 Suppress Active Behaviors and Cause Weight Loss in Hamsters. Brain Res. 1038:171-182, 2005.

Li, X. and F.C. Davis. Developmental expression of clock genes in the Syrian hamster. Develop. Brain Res. 158:31-40, 2005

Li, X.,  N. Sankrithi, and F.C. Davis, Transforming growth factor-alpha is expressed in astrocytes of the suprachiasmatic nucleus in hamsters: role of glial cells in circadian clocks.  NeuroReport 13:2143-2147, 2002.

Storch, K-F., Lipan, O., Leykin, I., Viswanathan, N., Davis, F.C., and Weitz, C.J.  Extensive and divergent circadian gene expression in liver and heart.  Nature 417: 78-83, 2002.

Kramer, A., F-C Yang, P.Snodgrass,  X. Li,  T. E. Scammell, F. C. Davis, and C. J. Weitz.  Regulation of daily locomotor activity and sleep by hypothalamic EGF receptor signaling. Science 294:2511-2515, 2001.

Furukawa,T., E.M. Morrow, T. Li, F.C. Davis, C.L. Cepko.  Retinopathy and attenuated circadian entrainment in Crx-deficient mice. Nature Genetics 23:466-470, 1999.

Grosse, J. and F.C. Davis.  1999. Transient entrainment of a circadian pacemaker during development by dopaminergic activation in Syrian hamsters. Brain Res. Bulletin 48: 185-194.

Grosse, J. and F.C. Davis.  1998. Melatonin entrains the restored circadian activity rhythms of Syrian hamsters bearing fetal SCN grafts. J. Neuroscience 18: 8032-8037.

Davis, F.C. and N. Viswanathan.  1998. Stability of circadian timing with age in Syrian hamsters. Am. J. Physiol. 275: R960-R968.

Gekakis, N., D. Staknis, H.B. Nguyen, F.C. Davis, L.D. Wilsbacher, D.P. King, J.S. Takahashi, and C.J. Weitz.  1998. Role of the CLOCK protein in the mammalian circadian mechanism. Science 280: 1564-1569.

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