Related Experiment Video
Updated: Jul 17, 2026
06:53
Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures
Published on: November 11, 2016
A stochastic model for circadian rhythms from coupled ultradian oscillators
Roderick Edwards1, Richard Gibson, Reinhard Illner
1Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada. edwards@math.uvic.ca
Theoretical Biology & Medical Modelling
|January 11, 2007
Summary
This study demonstrates that coupled ultradian oscillators can generate circadian rhythms, showing robustness against inherent stochasticity in protein binding and unbinding. The model confirms that deterministic behavior emerges from stochastic processes.
Area of Science:
- Biophysics
- Systems Biology
- Biochemistry
Background:
- Circadian rhythms are fundamental biological processes observed across diverse organisms.
- Previous models proposed coupling ultradian transcriptional-translational oscillators (TTOs) to generate circadian rhythms.
- The role of inherent stochasticity in protein binding/unbinding on circadian oscillations needed further investigation.
Purpose of the Study:
- To investigate the robustness of a proposed model for circadian rhythm generation via coupled TTOs.
- To determine if stochasticity in protein binding/unbinding affects the emergence of clear circadian oscillations.
- To mathematically prove the emergence of a deterministic model from a stochastic one.
Main Methods:
- Development of two versions of the TTO model: a stochastic version and a deterministic, time-averaged version.
- Mathematical rigorous proof demonstrating the emergence of the deterministic model from the stochastic model.
- Numerical simulations to compare results from both stochastic and deterministic models.
Main Results:
- The model demonstrates robustness to stochasticity in protein binding/unbinding, even at rates significantly slower than experimental values.
- Stochastic effects do not invalidate the observation of clear circadian oscillations.
- The deterministic, time-averaged system rigorously emerges as the fast-binding-rate limit of the full stochastic model.
Conclusions:
- The proposed model for circadian rhythm generation via coupled TTOs is robust to inherent molecular noise.
- Mathematical rigor confirms the relationship between stochastic and deterministic descriptions of the system.
- This work provides a validated framework for understanding the origin and mechanisms of circadian rhythms.
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...
01:30RLC Circuit as a Damped Oscillator
An RLC circuit combines a resistor, inductor, and capacitor, connected in a series or parallel combination.
Consider a series RLC circuit. Here, the presence of resistance in the circuit leads to energy loss due to joule heating in the resistance. Therefore, the total electromagnetic energy in the circuit is no longer constant and decreases with time. Since the magnitude of charge, current, and potential difference continuously decreases, their oscillations are said to be damped. This is...
Consider a series RLC circuit. Here, the presence of resistance in the circuit leads to energy loss due to joule heating in the resistance. Therefore, the total electromagnetic energy in the circuit is no longer constant and decreases with time. Since the magnitude of charge, current, and potential difference continuously decreases, their oscillations are said to be damped. This is...
01:17Design Example: Underdamped Parallel RLC Circuit
Consider designing an oscillator circuit, a crucial component in various electronic devices and systems. The objective is to create an oscillator circuit with specific characteristics: a damped natural frequency of 4 kHz and a damping factor of 4 radians per second. To accomplish this, a parallel RLC circuit is employed, known for its ability to sustain oscillations at a resonant frequency. In this case, the damping factor is pivotal in achieving the desired performance.
Starting with a fixed...
Starting with a fixed...