Effect of CCh pulses with rest time of R = 10 min on [Ca²⁺]_i oscillations.

(A) In this example, all four islets had a natural period, as seen in the inset, between 5.1–6.8 min (open circles) which entrained to 5 min (1:2) during the pulsing period (filled circle). The number of islets with identical oscillation periods before or during pulsing is indicated adjacent to the relevant circle. (B) The synchronized response of the group is evident by the emergence of a pronounced band at 5 min during the CCh pulsing. After the final pulse, 5 min oscillations persisted until the end of the Ca2+ measurement. See S10–S13 Figs for results from the remaining R = 10 min groups. (C) A compilation of the oscillation periods of all 20 islets tested prior to (open circles) and during pulsing (filled circle) with R = 10 min is shown.