Gain control in molecular information processing: lessons from neuroscience.

Statistical properties of environments experienced by biological signaling systems in the real world change, which necessitates adaptive responses to achieve high fidelity information transmission. One form of such adaptive response is gain control. Here, we argue that a certain simple mechanism of gain control, understood well in the context of systems neuroscience, also works for molecular signaling. The mechanism allows us to transmit more than 1 bit (on or off) of information about the signal independent of the signal variance. It does not require additional molecular circuitry beyond that already present in many molecular systems, and in particular, it does not depend on existence of feedback loops. The mechanism provides a potential explanation for abundance of ultrasensitive response curves in biological regulatory networks.