Laura Smale

 smale@msu.edu
Smale Lab
Curriculum Vitae

Research Interests

The primary focus of the research being conducted in my lab is on the neural mechanisms controlling circadian rhythms. This research is aimed at determining how these mechanisms differ in nocturnal and diurnal mammals. A small group of neurons in the mammalian hypothalamus called the suprachiasmatic nucleus (SCN) is responsible for the generation of 24 hour, "circadian," rhythms. To date, most research into the neural substrates controlling circadian rhythms has been done with nocturnal rodents. One reason is that there has been no suitable diurnal rodent model with which to investigate the issue.

We are working with Arvicanthis niloticus, a diurnal rodent recently imported from Africa. We are currently examining A. niloticus with respect to its circadian rhythms and the neural structures controlling them. We are testing the hypothesis that differences in some aspect of SCN function account for differences in rhythms of diurnal and nocturnal mammals. Some of our comparisons of the diurnal A. niloticus with the more commonly studied nocturnal species Rattus norvegicus have revealed interesting differences within the SCN. We are now determining if these patterns extend to closely related nocturnal and diurnal species from other taxonomic groups. We are also evaluating the hypothesis that diurnal and nocturnal species differ with respect to responses exhibited by other neural structures to signals emanating from the SCN.

In addition, we have been characterizing patterns of individual variability with respect to daily rhythms in A. niloticus. Whereas most individuals in the original animal colony were diurnal, a few were distinctly different, and nocturnal. We have been exploring the heritability of this difference in rhythm pattern, and characterizing behavioral, physiological and neural correlates of this difference. This line of work may lead to a better understanding of both the evolution of differences between day and night active animals, and the neural mechanisms underlying these differences.

Please feel free to contact me if you have any questions about my research.

Selected Publications

Search all publications in the NCBI Journal Database

Christopher M. Lambert, Kaz K. Machida, Laura Smale, Antonio A. Nunez,, and David R. Weaver, Analysis of the Prokineticin 2 System in a Diurnal Rodent, the Unstriped Nile Grass Rat (Arvicanthis niloticus). Journal of Biological Rhythms, Vol. 20 No. 3, June 2005 206-218

M. D. SCHWARTZ, A. A. NUNEZ AND L. SMALE, Differences in the Suprachiasmatic Nucleus and Lower Subparaventricular Zone of Diurnal and Nocturnal Rodents. Neuroscience 127 (2004) 13-23

Laura Smale, Theresa Lee, and Antonio A. Nunez, Mammalian Diurnality: Some Facts and Gaps. Journal of Biological Rhythms, October 2003