Schematic representations of the electrical stimulus protocols in the present study.

<p><b><i>A</i></b>, STET is three 100 Hz bursts of electrical stimuli. The inter-burst interval is 5 min. Each burst is simulated as a 3-s increase of [Ca²⁺]_s and [Ca²⁺]_d. Each tetanus increases k_{p_Raf,s} and k_{p_Raf,d} , and some summation of these increases is evident. <b><i>B</i></b>, WTET is a single 100 Hz burst. <b><i>C</i></b>, SLFS is a series of bursts, each of three stimuli at 20 Hz, with an inter-burst interval of 1 s, continuing for 15 min. This is simulated as a 15-min increase of [Ca²⁺]_s and [Ca²⁺]_d, and an increase of k_{p_Raf,s} and k_{p_Raf,d}. that lasts ∼25 min. <b><i>D</i></b>, WLFS is a 15-min train of single stimuli at 1 Hz.