CIRCADIAN RHYTHM
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 439 ▶ |
| Object type | Discipline oriented |
Any periodic behavior in living systems synchronized with the alternance of day and night.
Circadian rhythms are of cardinal importance for all living systems, specially human systems up to the highest societal level. Recent research by J.S. TAKAHASHI and M. HOFFMAN (1995, p.158-65) pinpointed J. MILLER's timer subsystem, which is ultimately located in the suprachiasmatic nucleus (SNC) in mammalian brains. The SNC is apparently heir to the pineal eye of reptiles. It acts as a “master circadian clock” that commands time-connected activities and seems to be ultimately under the control of a specific gene, or group of genes, since the activity rhythms of mice has been altered by induced genetic mutations.
It is moreover interesting to observe that any animal possesses organizationally closed devices at the physiological level, responding in precisely specific ways to environmental stimuli. The case of vegetals, not yet much researched until now, seems to be similar.