Send to

Choose Destination
Front Integr Neurosci. 2018 Mar 13;12:10. doi: 10.3389/fnint.2018.00010. eCollection 2018.

The Times of Our Lives: Interaction Among Different Biological Periodicities.

Author information

Departamento de Ciencia y TecnologĂ­a, Universidad Nacional de Quilmes (UNQ), CONICET, Buenos Aires, Argentina.


Environmental cycles on Earth display different periodicities, including daily, tidal or annual time scales. Virtually all living organisms have developed temporal mechanisms to adapt to such changes in environmental conditions. These biological timing structures-ranging from microsecond to seasonal timing-may have intrinsic properties and even different clock machinery. However, interaction among these temporal systems may present evolutionary advantages, for example, when species are exposed to changing climatic conditions or different geographic locations. Here, we present and discuss a model that accounts for the circadian regulation of both ultradian (less than 24-h) and infradian (more than 24-h) cycles and for the interaction among the three time scales. We show two clear examples of such interaction: (i) between the circadian clock and the seasonal regulation of the Hypothalamic-Pituitary-Thyroid (HPT) axis; and (ii) between the circadian clock and the hypothalamic-nigrostriatal (HNS) ultradian modulation. This remarkable interplay among the otherwise considered isolated rhythms has been demonstrated to exist in diverse organisms, suggesting an adaptive advantage of multiple scales of biological timing.


biological timing; circadian system; infradian rhythms; interaction; mathematical model; ultradian rhythms

Supplemental Content

Full text links

Icon for Frontiers Media SA Icon for PubMed Central
Loading ...
Support Center