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Nonadaptive fluctuation in an adaptive sensory system: bacterial chemoreceptor
Masatoshi Nishikawa1, Tatsuo Shibata
1Department of Mathematical and Life Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
Plos One
|July 9, 2010
Summary
Adaptive sensory systems, like bacterial chemotaxis, show perfect adaptation on average but retain noisy fluctuations. These fluctuations provide environmental information and enhance behavioral responses, enabling systems to adapt while sensing.
Area of Science:
- Biophysics
- Systems Biology
- Molecular Biology
Background:
- Sensory systems adapt to new signals after initial responses, preparing for diverse backgrounds.
- Biomolecular components (receptors, channels) in adaptation are subject to noisy thermal fluctuations.
- Adaptive properties emerge as statistical averages despite inherent molecular noise.
Purpose of the Study:
- To investigate a kinetic model of adaptive molecular systems.
- To determine if temporal stochastic fluctuations convey environmental information.
- To analyze the role of fluctuations in sensory system performance.
Main Methods:
- Theoretical analysis of a simple kinetic model for adaptive molecular systems.
- Examination of stochastic fluctuations in relation to environmental conditions.
- Modeling of bacterial chemotaxis as a case study.
Main Results:
- Adaptive systems demonstrate perfect adaptation on average.
- Temporal stochastic fluctuations are sensitive to environmental conditions.
- Bacterial chemotaxis models show nonadaptive fluctuations sensitive to ligand concentration, enhancing chemotaxis.
Conclusions:
- Stochastic fluctuations in adaptive sensory systems can carry environmental information beyond average behavior.
- These fluctuations allow systems to remain responsive to stimuli while transmitting subtle environmental cues.
- Utilizing noise enhances sensory system functionality and performance.
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