Figure 1

IPI histograms when the fish was without stimulus for 30 min (dashed lines) and stimulated by a electric pulse sent 20 ms (A) and 200 ms (B) after detecting a pulse from the fish (black and red lines respectively). A. The fish increased its frequency (shorter IPIs) compared to the control with a new high peak in 11 ms and discharging less 130 ms and 300 ms IPIs. B. There was a decrease in the frequency of the fish (longer IPIs) under stimulation, the peaks changed from 140 ms to 150 ms and 290 ms to 300 ms.