New Insights on Circadian Rhythms: Temperature's Impact on Biological Clocks

In a groundbreaking study led by Dr. Gen Kurosawa at the RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) in Japan, researchers have unveiled how the human biological clock maintains its 24-hour rhythm despite fluctuations in temperature. The study, published in PLOS Computational Biology on July 22, 2025, highlights the role of waveform distortion in the synchronization of our internal clocks with environmental changes.

Circadian rhythms, the natural cycles that govern sleep and wakefulness, are influenced by various external factors, including light and temperature. Traditional understanding posits that increased temperatures generally accelerate metabolic processes, potentially disrupting these rhythms. However, the findings from Kurosawa's team suggest that the biological clock adapts to these changes through a mechanism known as waveform distortion.

According to Dr. Kurosawa, “Our findings show that waveform distortion is a crucial part of how biological clocks remain accurate and synchronized, even when temperatures change.” This research utilized mathematical models derived from theoretical physics to analyze the rhythmic behaviors of mRNA molecules, which are essential for protein production linked to circadian cycles. The team employed the renormalization group method, a sophisticated approach adapted from physics, to extract critical dynamics from mRNA rhythms.

The study discovered that, at elevated temperatures, mRNA levels increase at a faster rate and decline more slowly, resulting in skewed, asymmetrical waveforms. This distortion is significant as it not only stabilizes the internal clock but also enhances its ability to synchronize with the day-night cycle. Experimental data from both fruit flies and mice corroborated these theoretical predictions, demonstrating observable waveform distortions at higher temperatures.

The implications of this research extend beyond basic biological understanding. Dr. Kurosawa indicated that the degree of waveform distortion could serve as a biomarker for various sleep disorders, jet lag, and aging-related issues. “Identifying the molecular mechanisms that contribute to this distortion can pave the way for better management of circadian-related health concerns,” he stated.

Experts in the field, such as Dr. Michael Rosbash, Nobel Prize winner and professor at Brandeis University, have acknowledged the significance of these findings, stating that “understanding how temperature affects circadian rhythms has profound implications for public health, especially in an era where climate change is becoming a critical factor in our daily lives.”

The study's results also resonate with contemporary societal challenges, as irregular light and temperature exposure have become commonplace due to modern lifestyles. As people navigate these environmental changes, understanding the underlying mechanisms of circadian regulation may enhance strategies for promoting better sleep hygiene and overall health.

Future inquiries will focus on how waveform distortion varies among different species and individuals, offering insights into personalized medicine approaches. As researchers continue to explore these dynamics, the potential for broader applications in various fields, including behavioral science and environmental health, remains promising. Dr. Kurosawa's work exemplifies the intersection of theoretical physics and biological research, showcasing how interdisciplinary approaches can yield transformative insights into fundamental biological processes.