With our growing awareness of the complexity underlying biological phenomena, our need for computational models becomes increasingly apparent. Due to their properties, biological clocks have always lent themselves to computational modelling. Their capacity to oscillate without dampening--even when deprived of all rhythmic environmental information--required the hypothesis of an endogenous oscil...

Susan Golden did not set out to become an expert in biological clocks, the internal timepieces that keep life on Earth adjusted to a 24-hour cycle. Instead, Golden, elected in 2010 to the National Academy of Sciences, wanted to identify the genes that underpin photosynthesis. However, her focus changed in 1986 with the discovery of biological clocks in cyanobacteria (1). Because cyanobacteria a...

Circadian rhythms are genetically determined biological oscillations evident in virtually all plants and animals, and even some prokaryotes. Circadian rhythms are generated by endogenous timing mechanisms referred to as biological or circadian clocks. Signature features of circadian clocks include an endogenous cycle length (period) of about 24 hr, daily sensitivity to resetting (entraining) st...

Feeding behavior, metabolism and circadian clocks are interlinked. Calorie restriction (CR) is a feeding paradigm known to extend longevity. We found that CR significantly affected the rhythms in the expression of circadian clock genes in mice on the mRNA and protein levels, suggesting that CR reprograms the clocks both transcriptionally and post-transcriptionally. The effect of CR on gene expr...

Circadian clocks exhibit the robustness of period and plasticity of phase against environmental changes such as temperature and nutrient conditions. Thus far, however, it is unclear how both are simultaneously achieved. By investigating distinct models of circadian clocks, we demonstrate reciprocity between robustness and plasticity: higher robustness in the period implies higher plasticity in ...

Biological rhythms and their temporal organization are adaptive phenomena to periodic changes in environmental factors linked to the earth's rotation on its axis and around the sun. Experimental data from the plant and animal kingdoms have led to many models and concepts related to biological clocks that help describe and understand the mechanisms of these changes. Many of the prevailing concep...

The lives of plants, animals, and human beings are all regulated by circadian clocks. In mammals, 24-hour rhythms of physiology and behavior are directed by a master clock in the suprachiasmatic nucleus (SCN) of the brain hypothalamus, which in turn entrains "slave" oscillators of similar molecular composition in most cells of the body. These peripheral clocks are interesting not only because t...

Although circadian rhythms in mammalian physiology and behavior are dependent upon a biological clock in the suprachiasmatic nuclei (SCN) of the hypothalamus, the molecular mechanism of this clock is in fact cell autonomous and conserved in nearly all cells of the body. Thus, the SCN serves in part as a "master clock," synchronizing "slave" clocks in peripheral tissues, and in part directly orc...

Many biological systems contain both positive and negative feedbacks. These are often classified as resonators or integrators. Resonators respond preferentially to oscillating signals of a particular frequency. Integrators, on the other hand, accumulate a response to signals. Computational neuroscientists often refer to neurons showing integrator properties as type I neurons and those showing r...

Rhythmicity is a ubiquitous phenomenon. Rhythmic temporal patterns are considered and important factor in therapeutics as effective treatments should work in conjunction with body's clocks. Te concept of chronobiology is well evidenced by the cyclic alterations of dosas in the body. The Ayurvedic way of living as well as healing has been developed keeping in mind these biological clocks so as t...