Education

Period of study	Name of University	Subject	Degree or    Professional License	Date of Award
1987 - 1990	Tel Aviv University	Life Sciences	B.Sc.	1990
1990 - 1992	Tel Aviv University magna cum laude	Zoology	M.Sc.	1992
1990 - 1992	Tel Aviv University	Education	Teaching certificate	1992
1993 - 1996	Tel Aviv University	Management	M.H.A.	1996
1992 - 1997	Tel Aviv University	Zoology	Ph.D.	1997

Title of Master's thesis: " Water and energy exchanges in desert and temperate hare populations (Lepus capensis)”.
Names of supervisor: Prof. A. Shkolnik, Tel Aviv University.

Title of Doctoral dissertation: "Coexistence among desert spiny mice: Ecological,physiological and biochemical aspects".
Names of supervisors:

Prof. A. Shkolnik, Department of Zoology, Tel Aviv University.
Prof.. T. Dayan, Department of Zoology, Tel Aviv University.
Prof. N. Zisapel, Department of Neurobiochemistry, Tel Aviv University

Further studies

Academic and professional experience

My main research interest is the interaction between physiological and endocronological processes and the evolutionary ecology of organisms and communities. Physiology and especially endocrinology of mammals are usually studied in the laboratory, and focus on humans and laboratory animal models. However, these systems have been shaped by evolutionary processes under natural conditions. Moreover, the properties of physiological and endocrinological systems influence evolutionary processes in individuals and populations and consequently contribute to structuring ecological communities. Understanding these processes, using a comparative approach will further our understanding of these systems on one hand, and of their involvement in ecological and evolutionary processes on the other hand. Part of my research is carried out in the field, using experimental ecological techniques, and part of it is carried out in the laboratory, using endocrinological and physiological methods, to the molecular level.

Research in my laboratory focuses on three related projects:

1. Daily rhythms, their plasticity and ecological significance:

Circadian rhythmicity is a fundamental characteristic of a species. It is an important component of its physiology, as well as to its social and ecological interactions. Nevertheless, the mechanisms determining nocturnal and diurnal activity are largely unknown, and most of what we know about mammals’ circadian physiology comes from studies on nocturnal mammals. In this study we use use Acomys russatus as an alternative animal model for the study of the neural mechanisms determining nocturnal and diurnal activity in mammals. In its natural habitat, A. russatus is competitively excluded by its nocturnal congener, A. cahirinus, from a nocturnal to a diurnal niche. We are taking advantage of this unique ecological phenomenon. Specifically, we study the effect of different non-photic cues on A. russatus circadian physiology, and study rhythmic processes (Fos, Per1 and Per2 expression) within the neural structures that regulate circadian rhythms, in order to determine if they are correlated with the different activity patterns exhibited by the two Acomys species, and with the different activity patterns exhibited by A. russatus. These experiments will help us to gain valuable insight into the integrated functioning and complexity of the central mechanisms that determine activity time, their plasticity, and to the interplay between ecology, neurophysiology, and circadian rhythms.

2. The roles of ecological and physiological selective forces in shaping rhythms biology and community structure in a rocky desert rodent system: (cooperation with Prof. Tamar Dayan)

The role of time in mediating ecological interactions and in shaping the structure of ecological communities is still poorly understood. Moreover, little research has focused on the role played by selective forces and evolutionary constraints in the evolution of activity patterns of animal species.
An excellent model system for the study of the role of temporal partitioning and the evolution of activity patterns is found at Ein Gedi, near the Dead Sea. Two congeners, the nocturnal common spiny mouse (Acomys cahirinus) and the diurnally active golden spiny mouse (A. russatus), coexist in rocky habitats. This is an unusual situation; because physiological, morphological, and behavioral adaptations often accompany a diurnal or nocturnal way of life, closely related species are generally active during the same part of the diel cycle.
We are currently carrying out an experimental study in four 1000 sq. m. field enclosures at Ein Gedi. Two enclosures hold mixed populations of both species, and serve as controls, while two are populated only with A. russatus, and serve as experiments. We study the roles of animal physiology, circadian rhythmicity, ambient temperatures, and food and water availability, as well as those of evolutionary constraints, in shaping motor activity patterns of desert small mammals, and the community structure at this rocky desert.

Results of this study will enable us to:

a) understand the precise motor activity rhythms of nocturnally active A. russatus;

b) compare the body temperature rhythms of nocturnally and diurnally active A. russatus;

c) estimate the cost in energy and water turnover of shift from nocturnal to diurnal activity of A. russatus;

d) understand the role of food and water availability in shaping the activity pattern of A. russatus.

3. Adaptation to food shortage in mammals of desert habitats: control of body mass

Body mass and composition is one of the most important characters of mammals and one that is extremely significant to fitness. Our study focuses on the physiological, endocrinological and biochemical mechanisms of adaptation to food shortage in relation to behavioral ecology, and the role of leptin in these adaptations. Specifically, we study how desert rodents that do not store food, survive food shortage periods. What are the mechanisms for fat accumulation and for reducing metabolism in response to food shortage, and what is the involvement of leptin in these adaptations?
The study focuses on the response of Acomys russatus, an omnivorous desert rodent that doesn’t store food, to food restriction and the possible involvement of uncoupling proteins in the reduction of energy expenditure in response to food shortage. We also study the response of Acomys russatus to high-energy diet, and the mechanism allowing fat accumulation in this species.

Recent publications:

Kronfeld-Schor, N., A. Haim, T. Dayan, N. Zisapel, M. Klingenspor, and G. Heldmaier. Seasonal thermogenic acclimation of diurnally and nocturnally active desert spiny mice. Physiological and Biochemical Zoology 73(1):37-44. 2000.

Shargal, E., N. Kronfeld-Schor, and T. Dayan. Population biology and spatial relationships of coexisting spiny mice of the genus Acomys. Journal of Mammalogy 81(4):1046-1052. 2000.

Kronfeld-Schor, N., Silvia, A.B. Kunz, T. H., Richardson, C. and Widmaier, E. P. Dissociation of leptin secretion and adiposity during pre-hibernation fattening in little brown bats. American Journal of Physiology 279:R1277-R1281. 2000.

Kronfeld-Schor, N., Silvia, A. B., Bicer, E., Mathews, P. T., Kunz, T. H., and Widmaier, E. P. Steroid-dependent up-regulation of adipose leptin secretion in vitro during pregnancy in mice. Biology of reproduction 63:274-280. 2000.

Kronfeld-Schor, N., Shargal, E., Haim, A., Dayan, T., N. Zisapel, and G. Heldmaier. Temporal partitioning among diurnally and nocturnally active desert spiny mice: Energy and water turnover costs. Journal of Thermal Biology 26:139-142. 2001.

Kronfeld-Schor, N., J. Zhao, B.A. Silvia, P.T. Mathews, S. Zimmerman, E.P. Widmaier, and T.H. Kunz. Hyperleptinemia in pregnant bats is characterized by increased placental leptin secretion in vitro. Endocrine 14 (2): 225-233. 2001.

Kronfeld-Schor, N., T. Dayan, M.E. Jones, I. Kremer, Y. Mandelik, M. Wollberg, Y. Yassur, and D. Gaton. Retinal structure and foraging microhabitat use of the golden spiny mouse. Journal of Mammalogy . 82 (4):1016-1025. 2001.

Kronfeld-Schor, N., T. Dayan, R. Elvert, A. Haim, N. Zisapel, and G. Heldmaier. On the use of the time axis for ecological separation: endogenous rhythmicity as an evolutionary constraint. American Naturalist. 158(4):451-457. 2001.

Kronfeld-Schor, N. and Dayan, T. Partitioning of time as an Ecological Resource. Annual Review of Ecology and Systematics . 2003. 34:153-81

Guter, A., Saltz, D., Dolev, A., and N. Kronfeld-Schor. Temporal, spatial, and gender influences on road mortality in otters: conservation implications. Israel Journal of Zoology. 51(3): 199-207. 2005.

Barel-Cohen, K., L. S, Shore, M. Shemesh, A. Wenzel, J. Mueller, and N. Kronfeld-Schor. Monitoring of natural and synthetic hormones in a polluted river. Journal of Environmental Management, 78 (1): 16-23. 2006

Pinter, N., Dayan, T., Eilam, D, and Kronfeld-Schor, N. Is aggression the driving force in the competition between common and golden spiny mice? Journal of Mammalogy 81 (1) 48:53. 2006.

Gutman, R, Choshniak, I., and Kronfeld-Schor, N. Defending body mass during food restriction in Acomys russatus: a desert rodent that does not store food. American Journal of Physiology. 290(4): R881-891. 2006.

Segal-Lieberman, G., Rubinfeld, H., Glick, M., Kronfeld-Schor, N., and I. Shimon. Melanin-Concentrating Hormone Stimulates Human Growth Hormone Secretion: A Novel Effect of MCH on Energy Balance via the Hypothalamic-Pituitary Axis? American Journal of Physiology 290:E982-988. 2006.

Cohen, R. and Kronfeld-Schor N. Individual variability and photic entrainment of circadian rhythms in golden spiny mice . Physiology & Behavior. 87: 563-574. 2006.

Roll, U., Dayan, T. and Kronfeld-Schor, N. On the role of phylogeny in determining activity patterns of rodents. Evolutionary Ecology. 20: 479-490. 2006.

Einat, H., Kronfeld-Schor, N., and Eilam, D. Short photoperiod induces a depression-like response in a diurnal rodent. Behavioral Brain Research .173:153-157. 2006.

Guter, A., Saltz, D., Dolev, A., and N. Kronfeld-Schor. Do otters occasionally visit Israel’s coastal Plain? IUCN otter specialist group bulletin 23 (1): 11-13. 2006

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Gutman, R., Yosha, D., Choshniak, I. , and Kronfeld-Schor N. Two strategies for coping with food shortage in desert golden spiny mice. Physiology & Behavior. 90: 95-102. 2007 .

Levy, O., Dayan, T. and Kronfeld-Schor N. 2007. The relationship between the golden spiny mouse circadian system and its diurnal activity: An experimental field enclosures and laboratory study. Chronobiology International 24(4):599-61 .

Kronfeld-Schor, N. and Dayan, T. Activity patterns of rodents: The physiological ecology of biological rhythms. Biological Rhythms Research, in press.

2001 - 2007	Roee Gutman (Co-advisor: Itzhak Choshniak) The role of body mass control in the adaptation of desert rodents to food shortage
2004 -	Rotem Cohen, Plasticity of circadian rhythms in golden spiny mice
2005 -	Ofir Levi, (Co-advisor: Tamar Dayan): Modeling climate effects: From basic principles to community structure
2005-	Eran Levin: Aspects in the biology and diet of Rehinopoma microphyllum (Co advisor Yoram Yom-Tov).
2007-	Ronit Hacmon-Keren: The mechanisms underlying starvation induced hyper activity and its ecological and medical relevance .

M.Sc students

	2002 - 2005	Amichai Guter: Ecology and conservation of the Eurasian otter in Israel .
	2003 - 2005	Moran Glik: The role of MCH and NPY in modulating energy balance.
	2003 -	Yaara Gatsera Sandomirsky: Parental care in common spiny mice .