Figure 3. Δ[Ca²⁺] and tension responses from fibres stimulated by a single shock and five shocks at 67 Hz.

A, slow-twitch responses (fibre, 062597.1). B, fast-twitch responses (averaged results from fibres 032596.2, 040596.1, 040896.1 and 040996.3). In A, the Δ[Ca²⁺] record following a single-shock has a peak amplitude of 7.6 μM, a time to half-rise of 3.7 ms, a time to peak of 4.5 ms and a half-duration of 8.2 ms; the corresponding values in B are 17.5 μM, 3.0 ms, 4.0 ms and 4.5 ms, respectively. For the tension responses in A, the values of time to half-rise, time to peak and half-duration are 55, 307 and 1360 ms, respectively (single shock) and 82, 342 and 1320 ms, respectively (multiple-shock); in B, the values are 16, 55 and 215 ms, respectively (single shock) and 34, 107 and 236 ms, respectively (multiple-shock). Temperature, 16 °C.