Heart Rate and Heart Rate Variability Assessment Identifies Individual Differences in Fear Response Magnitudes to Earthquake, Free Fall, and Air Puff in Mice
(A) Instant HR responses of an individual mouse during three trials of air puff stimuli, trial #1, trial #4 and trial #7. The red vertical dashed lines indicate the onset of the air puff stimuli (10 psi, 0.5 s). Robust increase of instant HR after stimulus onset was noted at trial #1. (B) Poincaré plots of the same mouse’s R-R intervals of 30-s pre-stimulus (grey line) and 30-s post-stimulus (red line) period in trial #1, trial #4 and trial #7. Prominent increase in heartbeat regularity during the 30-s post-stimulus period was noted in trial #1. (C) The average HR response to air puff (1st trial). (D) The average CV of R-R intervals upon 1st trial of air puff. (E) The average RMSSD of R-R intervals upon 1st trial of air puff. The average curves of 30-s pre-stimulus period were plotted as grey lines, whereas the average curves of 90-s post-stimulus period were plotted as red lines. The shadows around the average curves indicate error bars (SEM); n = 7.