Chronobiology: neural pacemakers of biological rhythms.

Biological rhythms are ubiquitous being demonstrable of any level of organization in living matter. However, the myriad of biological oscillators in peripheral organs are organized and synchronized by special structure, i.e., biological clocks, mostly located in central nervous system. Neural pacemakers show intrinsic properties which are illustrated and discussed. Understanding the meaning and function of neural oscillators is fundamental for those who wants to know how the biological structure of time is processed in living systems.