[Desynchronization: mechanisms of development from molecular to systemic levels]

Striking progress in the field of molecular chronobiology has been made during the last years. It renders us to reconsider some traditional viewpoints concerning circadian system functioning. Not only we are able now to explain basic concept of how clock genes pass through transcriptional and post-transcriptional pathways and how circadian system eventually "comes to life" at the cellular level, but we are also in position to speculate on how the whole organism constitutes its space-temporal order and how certain ultradians and infradians could be generated. Herein we propose a concept of multifuctorial genesis of chronomes and suggest terms such as "input rhythm" (or influencing rhythm) and "output rhythm" (or modulated rhythm). We stress on a viewpoint that the majority of investigated variables are multifuctorial by its nature because of vast net of regulatory mechanisms lied down in between the molecular basis of the clock and the output rhythms which are actually measurable by investigators. An attempt to follow down mechanisms of loss in the circadian temporal order (desynchronization) from the molecular level to that of a whole organism has been provided.