Fig. 5.

A: experiment showing that carbachol evoked a large Ca²⁺ transient and that caffeine (Caf; 10 mM) could evoke a further response when applied immediately after. Pretreatment with caffeine, however, prevented carbachol from evoking a Ca²⁺ transient. B: summary data for these experiments are shown graphically. C: typical record of the cellular response to carbachol in the continued presence of cyclopiazonic acid (CPA; 10 μM) showing gradual reduction of the response. *Statistical significance.