Ph. D., Vanderbilt University

   

Office:     414 Life Sciences Building

Phone:   1-419-372-2433

Email:     mgeusz@bgsu.edu

   

Research:

Circadian rhythms of cells

   

Research and Personal Page

   

 

   

Research Interests:

The primary interest of the laboratory is the organization of the circadian timing system of mice as a model for studying the impact of circadian physiology on human diseases. The interactions between the circadian clocks of the nervous system that generate near 24-hour rhythms and the tissues of several target organs are being examined by imaging rhythms in gene expression of whole mice and tissue explant cultures. These cycles are recorded using bioluminescent transgenic mice containing the firefly luciferase gene controlled by immediate-early gene promoters of mPer1, c-fos, and the major immediate-early gene of the human cytomegalovirus. Long-term imaging identified coupled circadian rhythms within the pancreas and cornea and others in midbrain nuclei controlling feeding behavior. These gene expression assays in live cells are combined with pharmacology, histology, neural recordings, and behavioral monitoring to identify the signaling mechanisms acting between the circadian clocks of the nervous system and the body.

Selected Publications:

Collaco A.M., S. Rahman, E.J.Dougherty, B.B. Williams and M.E. Geusz. 2005. Circadian regulation of a viral gene promoter in live transgenic mice expressing firefly luciferase. Molecular Imaging and Biology 7: 342-350.

Collaco, A.M. and M.E. Geusz. 2003. Imaging whole body immediate-early gene expression in haired and hairless transgenic mice. BMC Physiology 3: 8-19.

Sigworth, L.A., L. Liao, T.R. Chandler and M.E. Geusz. 2003. Luciferase expression controlled by a viral promoter in a mammalian circadian pacemaker. NeuroReport 14: 443-447.

Geusz, M.E. 2001. Bioluminescence imaging of gene expression in living cells and tissues. In: Methods in Cellular Imaging. Basics of Fluorescence, Fluorophores, Microscopy and Detectors. A. Periasamy, (ed.) Oxford Univ. Press, New York, pp. 395-408.

Nunemaker, C.S., R.A. DeFazio, M.E. Geusz, E.D. Herzog, G.R. Pitts and S.M. Moenter. 2001. Long-term recordings of networks of immortalized gonadotropin-releasing hormone neurons reveal spontaneous episodic patterns of action potential firing. J Neurophysiol 86: 86-93.

Sigworth, L.A., T.R. Chandler, L. Liao and M.E. Geusz. 2001. Luciferase imaging reveals distinct patterns of gene regulation in live brain slices. In: Bioluminescence and Chemiluminescence 2000. J. F. Case, P.J. Herring, B.H. Robison, SHD Haddock, LJ Kricka, PE Stanley, (eds.) World Scientific, Singapore. pp. 185-188.

Tosini, G. S. Doyle, M.E. Geusz and M. Menaker. 2000. Induction of photosensitivity in neonatal rat pineal gland. Proceedings of the National Academy of Sciences (USA) 97: 11540-11544.

Geusz, M.E., C. Fletcher, G.D. Block, M. Straume, N.G. Copeland, N.A. Jenkins, S.A. Kay and R.N. Day. 1997. Long-termmonitoring of circadian rhythms in c-fos gene expression from suprachiasmatic nucleus cultures. Current Biology 7: 758-766.

Herzog, E.D., M.E. Geusz, S.B. Khalsa,, M.Straume and G.D. Block. 1997. Circadian rhythms in mouse suprachiasmaticnucleus explants on multimicroelectrode plates. Brain Research 757: 285-290.

Geusz, M.E., R.G. Foster, W.J. DeGrip and G.D. Block. 1997. Opsin-like immunoreactivity in the circadian pacemaker neurons and photoreceptors in the eye of the opisthobranch mollusk Bulla. Cell and Tissue Research 287: 203-210.

Block, G., M. Geusz, S. Khalsa, and S. Michel. 1995. A clockwork Bulla: Cellular study of a model circadian system. Seminars in the Neurosciences 7: 37-42.

Geusz, M.E., and G.D. Block. 1994. Intracellular calcium in the entrainment pathway of molluscan circadian pacemakers. Neuroscience and Biobehavioral Reviews 18: 555-561.

Tominaga, K., M.E. Geusz, S. Michel, and S.T. Inouye. 1994. Calcium imaging in organotypic cultures of the rat suprachiasmatic nucleus. NeuroReport 5: 1901-1905.

Geusz, M.E., S. Michel and G.D. Block. 1994. Intracellular calcium responses of circadian pacemaker neurons measured with fura-2. Brain Research 638: 109-116.

Michel, S., M.E. Geusz, J.J. Zaritsky and G.D. Block,. 1993. Circadian rhythm in membrane conductance expressed in isolated neurons. Science 259: 239-241.

Block, G. D., S.B.S. Khalsa, S.B.S., G.D. McMahon, S. Michel, and M.E. Geusz. 1993. Cellular mechanisms of biological timekeeping. International Review of Cytology 146: 83-144.

Geusz, M.E., and G.D. Block. 1992. The retinal cells generating the circadian small spikes in the Bulla optic nerve. Journal of Biological Rhythms 7: 255-268.

Geusz, M.E., and T.L. Page. 1991. An opsin-based photopigment mediates phase shifts of the Bulla circadian pacemaker. Journal of Comparative Physiology A 168: 565-570.

Geusz, M.E., and T.L. Page. 1990. The circadian rhythm and photosensitivity of small impulses of the Bulla eye. Journal of Comparative Physiology A 166: 795-801.