Figure 21

Secondary [Ca²⁺] _myo transients induced by "tail currents". Figure 21: The stimulation protocol used is a pulse of amplitude (-40 mv to +50 mv) with pulse duration T _p increasing from 50 ms (trace 1) to 200 ms (trace 7) in steps of 25 ms. (A) A cartoon depicting the voltage clamp stimulus protocol where, pulse duration (T _p ) is varied to obtain traces 1-7 and the clamp potential transition time (T _t ) fixed at 1 ms. (B) I _Ca,L tail currents elicited during repolarization from +50 mv to -40 mv. (C) Open probability of the RyR channel indicating gradual recovery from the refractory period (D) [Ca²⁺] _jSR traces show increase in RyR release with increasing pulse duration as a result of adequate RyR channel recovery. (E) Cytosolic calcium transients indicate secondary RyR release caused by tail currents.