As changes in cytosoiic free ca2+ play key
roles in coupling responses in neutrophils, it is important
to locate and identify ca2+ storage sites within these
cells. Here, recent data is presented which highlights the
functional link between rnicroanatomical structure and
cell signailing function. Fluorescent opticai probes for
cytosolic free ca2+ have been used, together with
organelle specific markers. We present evidence from
conventional fluorescence microscopy, together with
ratiometric and confocal laser scanning fluorescence
microscopy, which pin-points two celiular locations for
ca2+ within the neutrophil; one within the nuclear lobes,
and the other towards the ceii periphery. Knowledge of
these two locations provides a clear insight into how
signailing in this cell type is regulated and provides a
framework for explaining how specific stimuli act to
produce specific responses
