Related Experiment Video
Updated: Jul 3, 2026
06:53
Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
Two decades of circadian time
M H Hastings1, E S Maywood, A B Reddy
1Division of Neurobiology, MRC Laboratory of Molecular Biology, Cambridge, UK. jacques.epelbaum@broca.inserm.fr
Journal of Neuroendocrinology
|July 8, 2008
Summary
Our understanding of circadian rhythms has evolved, revealing numerous local body clocks beyond the brain's master clock. This discovery impacts physiology and disease, paving the way for new therapies.
Area of Science:
- Chronobiology
- Molecular Biology
- Physiology
Background:
- Circadian rhythms are fundamental to physiology, historically viewed as 'black boxes'.
- Recent advances reveal autoregulatory transcriptional/post-translational feedback loops as the molecular basis of these rhythms.
- The suprachiasmatic nucleus (SCN) is recognized as the master pacemaker, but not the sole circadian clock.
Purpose of the Study:
- To summarize the paradigm shift in understanding circadian clocks.
- To highlight the discovery and implications of dispersed local circadian clocks throughout the body.
- To underscore the role of molecular insights in advancing chronobiology.
Main Methods:
- Review of molecular components and feedback loop mechanisms.
- Analysis of the suprachiasmatic nucleus (SCN) as a central pacemaker.
- Exploration of the systemic synchronization of local clocks.
Main Results:
- Circadian clocks are not confined to the SCN but are abundant throughout the body.
- These local clocks regulate cellular metabolism and are synchronized by the SCN.
- Clock dysfunction is implicated in various metabolic and neurological conditions.
Conclusions:
- The discovery of dispersed local clocks revolutionizes our understanding of physiology and disease.
- Molecular frameworks are crucial for these insights.
- Future research on systems-level clock function will drive novel therapeutic strategies for major illnesses.
Related Concept Videos
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:19Circadian Rhythms and Gene Regulation
The biological clock is involved in many aspects of regulating complex physiology in all animals. It was in 1935 when German zoologists, Hans Kalmus and Erwin Bünning, discovered the existence of circadian rhythm in Drosophila melanogaster. However, the internal molecular mechanisms behind the circadian clock remained a mystery until 1984, when Jeffrey C. Hall, Michael Rosbash, and Michael W. Young discovered the expression of the Per gene oscillating over a 24-hour cycle. In subsequent years,...
02:45Biological Clocks and Seasonal Responses
The circadian—or biological—clock is an intrinsic, timekeeping, molecular mechanism that allows plants to coordinate physiological activities over 24-hour cycles called circadian rhythms. Photoperiodism is a collective term for the biological responses of plants to variations in the relative lengths of dark and light periods. The period of light-exposure is called the photoperiod.
01:15Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
01:24Sleep-Wake Cycles
Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
01:22Generation Time
Bacterial generation time, the period required for a bacterial population to double during its exponential growth phase, serves as a critical measure of microbial growth dynamics under optimal conditions. This parameter varies significantly across bacterial species and can be influenced by factors such as temperature, pH, and the availability of nutrients. For example, Escherichia coli can achieve a generation time of approximately 20 minutes, while Mycobacterium tuberculosis exhibits a much...