Imaging of Ca2+ transients induced in Paramecium cells by a polyamine secretagogue

In Paramecium tetraurelia cells analysis of transient changes in Ca2+ concentration, [Ca2+]i, during aminoethyldextran (AED) stimulated synchronous (1 to 10 mM for exocytosis to occur in response to AED. In conclusion, our data indicate: (i) correlation of cortical [Ca2+]i transients with exocytosis, as well as (ii) occurrence of a similar signal transduction mechanism in mutant cells where target structures may be defective or absent