Design Principle of Adaptation Circuits

From Q-bio

Adaptation is a common feature in sensory and other biochemical networks. To elucidate the network topologies conducive for adaptation and their underlying design principles, we performed an exhaustive computational study of all 3-node topologies. We found that there are two classes of minimal topologies that can achieve robust adaptation: a single negative feedback loop with a buffering node and a single negative feed-forward loop. Each class has its own adaptation mechanism and corresponding requirement for key circuit’s parameters. We found that more complex topologies can also perform adaptation. All these complex topologies are, however, combinations of and/or extensions from the minimal topologies and as such can possess greater functional ability. Our results can be summarized with a design table for adaptation circuits that provides the topological building blocks and the rules of their extensions and combinations for desired functional specifications.