Figure 3. Human myotubes fatigue in response to continuous electrical stimulation in vitro.
Representative recording of force produced by cultured human myotubes, calculated from real time measurements of cantilever deflection using our laser and photo-detector system. Recordings from a single cantilever at different experimental time-points are overlaid to illustrate the effect of chronic broad-field electrical stimulation on force production over time. Stimulation was started at time = 0 seconds and continued at a frequency of 1 Hz throughout the time course of the study. For both time-points, raw data (in Volts) was converted to a measurement of myotube force (in nano-Newtons), using a modified Stoney’s equation, and re-plotted.