Cellular sensory mechanisms for detecting specific fold-changes in extracellular cues.

摘要: Cellular sensory systems often respond not to the absolute levels of inputs but fold-changes in inputs. Such a property is called fold-change detection (FCD) and important for accurately sensing dynamic changes environmental signals presence fluctuations their levels. Previous studies defined FCD as input-scale invariance proposed several biochemical models that achieve such condition. Here, we prove previous can be approximated by log-differentiator. Although log-differentiator satisfies requirement, its response amplitude duration strongly depend on input timescale. This creates limitations specificity repeatability detecting Nevertheless, with cells has been reported context Drosophila wing development. Motivated this fact extending models, here propose two possible mechanisms repeatability. One integrate-and-fire type: system integrates rate temporal change makes when integrated value reaches constant threshold, followed reset value. The other threshold occurs level whose multiplied certain after each response. These implemented biochemically appropriately combining feed-forward feedback loops. main difference between memory history; discuss ways distinguish experimentally.