Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

Feb 6, 2013Journal of visualized experiments : JoVE

Measuring daily activity patterns in rodents using running wheels

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗

Abstract

Voluntary running-wheel activity in nocturnal rodents varies significantly with the time of day.

Nocturnal rodents, such as rats, hamsters, and mice, show increased running-wheel activity during the night.
Running-wheel activity serves as a reliable measure of the output from the master circadian clock located in the suprachiasmatic nucleus (SCN).
Circadian rhythms in running-wheel activity align with the environmental light-dark cycle through a process known as entrainment.
In constant darkness, running-wheel activity can reveal subjective time-of-day, referred to as circadian time (CT).
The presence of an environmental light-dark cycle defines the time-of-day as zeitgeber time (ZT).
Extra-SCN brain regions may also contribute to daily activity rhythms, as seen in food-anticipatory behaviors.

AI simplified

When rodents have free access to a running wheel in their home cage, voluntary use of this wheel will depend on the time of day. Nocturnal rodents, including rats, hamsters, and mice, are active during the night and relatively inactive during the day. Many other behavioral and physiological measures also exhibit daily rhythms, but in rodents, running-wheel activity serves as a particularly reliable and convenient measure of the output of the master circadian clock, the suprachiasmatic nucleus (SCN) of the hypothalamus. In general, through a process called entrainment, the daily pattern of running-wheel activity will naturally align with the environmental light-dark cycle (LD cycle; e.g. 12 hr-light:12 hr-dark). However circadian rhythms are endogenously generated patterns in behavior that exhibit a ~24 hr period, and persist in constant darkness. Thus, in the absence of an LD cycle, the recording and analysis of running-wheel activity can be used to determine the subjective time-of-day. Because these rhythms are directed by the circadian clock the subjective time-of-day is referred to as the circadian time (CT). In contrast, when an LD cycle is present, the time-of-day that is determined by the environmental LD cycle is called the zeitgeber time (ZT). Although circadian rhythms in running-wheel activity are typically linked to the SCN clock, circadian oscillators in many other regions of the brain and body could also be involved in the regulation of daily activity rhythms. For instance, daily rhythms in food-anticipatory activity do not require the SCN and instead, are correlated with changes in the activity of extra-SCN oscillators. Thus, running-wheel activity recordings can provide important behavioral information not only about the output of the master SCN clock, but also on the activity of extra-SCN oscillators. Below we describe the equipment and methods used to record, analyze and display circadian locomotor activity rhythms in laboratory rodents.

Full Text

Full text is available at the source.

View full text ↗

Recording and Analysis of Circadian Rhythms in Running-wheel Activity in Rodents

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief