LONG-TERM CHEMOTAXIS OF NEUTROPHILS IN STABLE GRADIENTS - PRELIMINARYEVIDENCE OF PERIODIC BEHAVIOR

We observed and recorded the behavior of human neutrophils in stable l inear gradients of the chemotactic attractant f-Met-Leu-Phe in a recen tly developed, direct-viewing, chemotaxis chamber. The cells were kept cold for the first hour after setting up the chemotaxis chamber in or der to establish a stable gradient before allowing the cells to spread and begin to move by warming them up to 37-degrees-C. We found that t he cells showed very significant chemotaxis at different times through out the 2-hour period of observation but, unexpectedly, the activity o ccurred in periodic or quasi-periodic cycles during which the cells en tered phases of undirected motility lasting for several minutes. We di scuss whether the periodicity is a population or single cell-based phe nomenon and briefly speculate on its possible analogy to the well-know n periodic chemotaxis of slime mould amoebas.