Fig. 1.

Ryanodine and thapsigargin abolish caffeine-evoked CICR in Purkinje cells. A Purkinje cell was filled with 200 μm Oregon Green 488 BAPTA-1 via a whole-cell recording pipette, and 40 mm caffeine was applied using a 5 sec pressure puff from a nearby micropipette. Fluorescence measurements were restricted to a small area that included the Purkinje cell soma and proximal dendrites. A, In control conditions, a ΔF/F signal was recorded (left) in response to caffeine application (solid bar). Bath application of 10 μm ryanodine abolished this ΔF/F signal. The time course is shown on the right, with the solid bar indicating ryanodine application. B, Similar results were found for bath application of 10 μmthapsigargin. Representative traces are averages of four or five trials.