Neutrophil oscillations: temporal and spatiotemporal aspects of cell behavior.

Neutrophil activation is an essential event in inflammatory responses. How cells coordinate, integrate, manage, and distribute information on physiologically-relevant timescales are not well understood. Although neutrophil oscillators have been known for many years, their biological roles have not been identified. We suggest that intracellular oscillators (such as NAD(P)H, pH, calcium, and so on) account for functional oscillations (e.g., superoxide and NO production, cytolytic marker release, pericellular proteolysis, and actin assembly). In addition to these well-known temporal oscillations, we have recently discovered self-organized traveling chemical waves in neutrophils; these waves respond to extracellular signals and have distinct origins that coincide with a cell's uropod, lamellipodium, or adherence site. The fundamental physico-chemical features of cell chemistry will have an increasing role in our understanding of leukocyte function.