Figure 1. Experimental protocol.

Cells were seeded on day 0. On day 4 the samples were either sham-exposed or treated (TR) for 12 h or 24 h with 5-minute pulses of 0.57 MHz, sine wave current at a density of 50 µA/mm². The treatment and sham-exposure intervals were followed by an 18-h lapse of additional incubation (42 h; POST-TR).