  Most sensory cells use surface receptors to detect environmental stimuli and
initiate downstream signaling. Cooperative interactions among sensory receptors
is known to play a crucial role in enhancing the sensitivity of biochemical
processes such as oxygen sensing by hemoglobin, but whether cooperativity
enhances the fidelity with which a system with multiple receptors can
accurately and quickly detect a signal is poorly understood. We model the
kinetics of small clusters of receptors in the presence of ligand, where the
receptors act independently or cooperatively. We show that the interaction
strength and how it is coupled to the dynamics influences the macroscopic
observables. Contrary to recent reports, our analysis shows that receptor
cooperativity can increase the signal-to-noise ratio, but this increase depends
on the underlying dynamics of the signaling receptor cluster.
