Figure 4. The effects of ryanodine on the [Ca²⁺]_i transients elicited by a pair of voltage pulses.

A, traces show (from top to bottom): [Ca²⁺]_i, membrane potential and I_Ca elicited under control conditions (left) and in the presence of 5 μm ryanodine in the pipette solution (right, different cell). B, ryanodine abolished the difference between the mean value of calculated unit [Ca²⁺]_i transients in response to the first (UT₁) and second (UT₂) voltage pulses. Values are means ±s.e.m. (n = 7).