Living systems are capable of processing multiple sources of information simultaneously. This is true even at the cellular level, where not only coexisting signals stimulate the cell, but also the presence of fluctuating conditions is significant. When information is received by a cell signaling network via one specific input, the existence of other stimuli can provide a background activity –or chatter– that may affect signal transmission through the network and, therefore, the response of the cell. Here we study the modulation of information processing by chatter in the signaling network of a human cell, specifically, in a Boolean model of the signal transduction network of a fibroblast. We observe that the level of external chatter shapes the response of the system to information carrying signals in a nontrivial manner, modulates the activity levels of the network outputs, and effectively determines the paths of information flow. Our results show that the interactions and node dynamics, far from being random, confer versatility to the signaling network and allow transitions between different information-processing scenarios.

This work has been financially supported by the Spanish Network of Multiple Sclerosis (REEM, Instituto de Salud Carlos III), the Fundacion Mutua Madrileña (Spain), the Ministerio de Ciencia e Innovacion (project FIS2009-13360 and I3 program), and the Generalitat de Catalunya (project 2009SGR1168). P.R. is supported by a FI grant from the Generalitat de Catalunya. A.J.P. was supported by the Juan de la Cierva program of the Ministerio de Ciencia e Innovacion (Spain). J.G.O. also acknowledges financial support from the ICREA foundation