Figure 10

Graded CICR. Figure 10: SR calcium release graded by the trigger current I_Ca,L,TT. (A) - (i) Decreasing trigger current I_Ca,L,TT(ii) With decreasing trigger current, RyR open probability shows a graded decrease in its peak as well as an increasing delay in its onset (iii) Cytosolic calcium transient follows the trend shown by the RyR release channel (a graded decrease in peak and increasing delay in onset) (iv) RyR open probability vs [Ca²⁺] _ryr for increasing trigger current I_Ca,L,TT. (B)- (i)Concentration profile in the dyad as a result of RyR release caused by a largest trigger current (see part A(i)) (ii)Concentration profile in the dyad as a result of RyR release caused by a smallest trigger current (see part A(i)) (iii) With decreasing trigger current, RyR open probability shows a graded decrease in its peak as well as an increasing delay in its onset (shown on an expanded time scale) (iv)Difference in concentration between the mouth of the DHP and Ry-sensitive Ca²⁺ channels. (Inset shows the cross-over when this difference becomes negative indicating trigger current dependent latency involved in release).