在其關(guān)于布朗運動的研究中，愛因斯坦意識到,，處于靜止?fàn)顟B(tài)的一種物質(zhì)的隨機(jī)分子運動也會影響到其他東西,，比如說影響到它對于一個在外力作用下而穿過自己的粒子的阻力。這個現(xiàn)象后來被總結(jié)為“波動-響應(yīng)定律”,，但它是否適用于活細(xì)胞（活細(xì)胞的運動是遠(yuǎn)離平衡態(tài)的）仍然是一個尚未回答的問題,。Park等人利用在細(xì)菌趨化現(xiàn)象研究中有可能實現(xiàn)的小尺度測量發(fā)現(xiàn),，“波動-響應(yīng)定律”的確適用于單個細(xì)胞中細(xì)胞行為的時間波動（噪音）與細(xì)胞對外界的響應(yīng)之間的關(guān)系。他們提出了確定生化網(wǎng)絡(luò)中哪些特征使其內(nèi)部狀態(tài)與其對外部刺激的響應(yīng)耦合在一起的方式,。（生物谷Bioon.com）
生物谷推薦原文出處：
Nature doi:10.1038/nature09551
Interdependence of behavioural variability and response to small stimuli in bacteria
Heungwon Park,William Pontius,Calin C. Guet,John F. Marko,Thierry Emonet& Philippe Cluzel
The chemotaxis signalling network in Escherichia coli that controls the locomotion of bacteria is a classic model system for signal transduction1, 2. This pathway modulates the behaviour of flagellar motors to propel bacteria towards sources of chemical attractants. Although this system relaxes to a steady state in response to environmental changes, the signalling events within the chemotaxis network are noisy and cause large temporal variations of the motor behaviour even in the absence of stimulus3. That the same signalling network governs both behavioural variability and cellular response raises the question of whether these two traits are independent. Here, we experimentally establish a fluctuation–response relationship in the chemotaxis system of living bacteria. Using this relationship, we demonstrate the possibility of inferring the cellular response from the behavioural variability measured before stimulus. In monitoring the pre- and post-stimulus switching behaviour of individual bacterial motors, we found that variability scales linearly with the response time for different functioning states of the cell. This study highlights that the fundamental relationship between fluctuation and response is not constrained to physical systems at thermodynamic equilibrium4 but is extensible to living cells5. Such a relationship not only implies that behavioural variability and cellular response can be coupled traits, but it also provides a general framework within which we can examine how the selection of a network design shapes this interdependence
