Laura Smale, PhD
Professor, Psychology, Zoology
Ph.D., 1987, University of California-Berkeley
Location222 Giltner Hall
The primary focus of the research being conducted in my lab is on the neural mechanisms controlling 24 hour (circadian) rhythms. A small group of neurons in the mammalian hypothalamus called the suprachiasmatic nucleus (SCN) is responsible for the generation of circadian rhythms. To date, most research into the neural substrates controlling these rhythms has focused on the SCN and on other brain regions coupled to it, and almost all of this has been done on nocturnal animals. Much of the work that we do in my lab is aimed at determining how these mechanisms are different in diurnal ones, and focuses on a day-active rodent from Africa, Arvicanthis niloticus, otherwise known as the unstriped Nile grass rat. We are using these animals to identify the neural mechanisms that make some animals diurnal and others nocturnal. Our comparisons of grass rats with more commonly studied (night-active) lab rats (Rattus norvegicus) have revealed that, though there are some differences, most features of the SCN are similar in the two species. We are therefore focusing most of our attention on the relationships between the oscillations within the SCN and those in brain regions beyond it.
In addition to our work on issues related to species differences we have been examining plasticity within individuals and differences between individuals. Part of this also uses grass rats because, although most individuals in this species are diurnal, some exhibit more nocturnal patterns under some conditions. We are examining the neural mechanisms associated with these differences in order to identify mechanisms responsible for the negative consequences of shift work. Another way that we are exploring plasticity of circadian systems is by examining changes in the nervous system associated with changes in daily rhythms that occur as females transition from one reproductive state to another, such as from a non-pregnant to a pregnant state. All of our work is motivated both by our desire to better understand basic behavioral neuroscience and by our hopes of contributing to the improvement of human health and well being.