Fig. 6. SR Ca²⁺ release in burbot myocytes does not affect the inactivation kinetics of I_Ca. Representative recordings of I_Ca at 4°C (A) or 11°C (B) on the first pulse after caffeine application (SR empty) and the 25th pulse after caffeine application (steady-state SR Ca²⁺ content). Recordings are superimposed. Tau of inactivation was calculated by fitting a single exponential function to the decaying portion of I_Ca. For clarity, only the fit for 25th pulse is shown at each temperature (red lines). (C) Values are means ± s.e.m. from 9 myocytes at 4°C and 16 myocytes at 11°C, 1, 5, 10 and 25 pulses after caffeine application. ^*Inactivation of I_Ca was faster at 11°C than at 4°C (Student's t-test, P<0.05).