Temporal segregation in signalling: a novel mechanism in human neutrophils

The ability of neutrophils to carry out chemotaxis in response to low chemoattractant concentrations, but arrest their motility when exposed to higher concentrations of the same substance, has fascinated investigators for years. By analyzing the temporal characteristics of the morphological responses, corresponding to chemotaxis and cell arrest, we have recently discovered that the choice between them is made by transduction of the continuous binding process into either single or multiple stimuli within defined time intervals, initiating chemotaxis or cell arrest, respectively. Both experimental and theoretical lines of evidence are presented to support the validity of this unique mechanism.