Many, if not most, biochemical, physiological and behavioral parameters exhibited by organisms show daily fluctuations and most of these daily rhythms persist in constant conditions, thus demonstrating that they are driven by endogenous oscillators. The rhythms that persist in constant conditions with a period close to 24 hours are called circadian rhythms. Circadian pacemakers -i.e., the endogenous oscillator(s) that generate the rhythm - have been localized to particular cells and tissues in several cases. In a smaller number of cases - as for the mammalian suprachiasmatic nucleus (SCN) - these localized oscillators have been demonstrated to drive rhytmicity of the majority of the behavioral and physiological rhythms of the organisms.

It is now generally recognized that circadian system of higher organisms ( human included ) is composed of multiple oscillators (i.e., they are multioscillatory systems) that act in concert to control vert rhythmic behavior, but unfortunately the roles that these oscillators play in the control of the animal's rhythmicity remains largely unknown. Even more obscure are the interactions between the retinal and the hypothalamic circadian clocks and the contributions that each of these clocks have on the final circadian organization. Recent studies have shown that the molecular mechanism driving circadian rhythmicity in mammals involves a transcriptional feedback loop similar to that described for Drosophila.

The main research interest in my laboratory focuses on the circadian organization of the mammals. Our studies try to understand which are the mechanisms (molecular, cellular and physiological) that are responsible to maintain the different component of the circadian system synchronized and the effect that the uncoupling among different oscillators may produce. The laboratory use a wide array of techniques to measure rhythmic behavior (locomor activity, sleep and wake cycle), physiology (body temperature) and gene expression (real time quantitative PCR, quantitative in situ hybridization) in order to create a coherent picture of the circadian organization in mammals. In particular, in the last year we start to be interested in the effects that alteration of the circadian system (jet-lag, altered light:dark cycled or internal desynchronization) may produce on the animal at the level of performance and well being.

The laboratory is supported by grants from the National Institute of Health, National Science Foundation and National Space Biomedical Research Institute.