Fig. 7. cADPR failed to modulate STOCs. cADPR (; 50 µM) had no significant effect on the amplitude or frequency of STOCs (ii and expanded time base i) evoked by membrane depolarization from –70 mV to –20 mV (iv) or on [Ca²⁺]_c (iii). By contrast, caffeine (10 mM, v) increased [Ca²⁺]_c and evoked a transient outward current after which STOCs were suppressed, presumably as a result of store depletion (iii). There was no change in the probability of a STOC occurring (P_STOC; vi) before (100 seconds) and after (150 seconds) cADPR (vi; n=7; P>0.05).