zeitgeber


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zeitgeber

(tsīt′gĕb′ər, zīt′-)
n.
An external stimulus or cue, such as daylight or a regularly repeated occurrence, that serves to regulate an organism's biological clock.

zeitgeber

A factor in the environment that has periodicity and is capable of synchronising the endogenous circadian rhythm into a 24-hour cycle. Without zeitgebers, the free-running human clock has long been believed to be about 25.3 hours; more recent work by Charles A. Czeisler MD, PhD, pegs the internal human clock at 24 hours and 11 minutes, ±16 minutes.

zeitgeber

Zeit, German, time, geber, keeper A factor in the environment with a periodicity, capable of synchronizing the endogenous circadian rhythm into a 24-hr cycle; without zeitgebers, the free-running human clock is 25.3 hrs. See Circadian rhythm, Jet lag, Shift work, Sleep disorders. Cf REM sleep.

zeitgeber

(tsīt′gā″bĕr, zīt′) [Ger. Zeitgeber, timekeeper]
Any of the mechanisms in nature that keep internal biological clocks synchronized (entrained) with the environment. Zeitgebers can be physical, involving light or temperature (e.g., sunrise, sunset), or social, involving regular activities (e.g., consistent mealtimes).
References in periodicals archive ?
regular meals and daily routine and a regular bedtime routine) that provide additional zeitgebers are also put in place.
Bright light therapy was unsuccessful for one child, and the other three children were treated using forced waking and regular daytime schedules and night routines that acted as zeitgebers.
Zeitgeber time (ZT): A standardized 24-hour notation of the phase in an entrained circadian cycle in which ZT 0 indicates the beginning of day, or the light phase, and ZT 12 is the beginning of night, or the dark phase.
3rd: Zeitgebers (events in nature that tell the time of year) for this week include occasional sightings of foxes and coyotes frolicking at night in their mating rituals, starlings and sparrows scouting for nesting areas in and around your eaves.
10th: Zeitgebers for this week include the increasing frequency of cardinal and titmouse song in the morning, the occasional call of a blue jay, the appearance of pileated woodpeckers at feeders as nesting time gets underway, the cracking of a few pussy willow catkins, the falling of the prickly sweet gum seed balls, and an allergic response by some people to pollen from pine trees.
8: Zeitgebers for this week: Honeysuckle bushes leaf out.
Frank said based on her clinical experience--she has been following some patients for 10-12 years--people with bipolar disorder are vulnerable to disruptions in their social zeitgebers throughout life.