New Insights into Biological Clocks: Unclocklike Oscillators with Frequency Memory

Recent research by Christian Mauffette Denis and Paul François, titled "Unclocklike oscillators with frequency memory for the entrainment of biological clocks," presents new insights into how biological clocks adapt their internal frequencies in response to external signals. The study, submitted to arXiv on May 8, 2024, and revised on August 26, 2024, proposes a novel model of oscillators that can change their frequency based on memory variables. This behavior deviates from traditional one-dimensional clock models and limit-cycle models, suggesting a new category of oscillatory behavior termed 'unclocklike.'

The authors conducted experiments focusing on the vertebrate segmentation clock, which is crucial during embryonic development. Their findings indicate that these biological oscillators can actively modify their internal frequencies to align with external cues. The research explores two distinct models for controlling the memory variable: one that employs a smooth phase-averaging memory field and another that uses a pulsatile, phase-dependent activation.

Key phenomena observed in this study include:

• Broad Arnold tongues, which represent the range of frequencies over which the oscillator can synchronize with external signals.
• An entrainment phase that stabilizes even with frequency detuning.
• New behaviors such as hysteresis in entrainment and bistability in the frequency of the oscillator.
• Probabilistic entrainment, indicating that the synchronization process can have variable outcomes.

These findings have significant implications for understanding biological rhythms and could lead to advancements in fields such as developmental biology and chronobiology. The ability to test these unclocklike properties experimentally opens new avenues for research into how biological systems maintain their timing and adapt to environmental changes.

For further details, the full paper is available at arXiv:2405.05180.