Fig. 1.
Mean (+ SEM) heart rate (Panel A), SDNN index (Panel B), and amplitude of respiratory sinus arrhythmia (Panel C) in paired and isolated prairie voles prior to and during a 10-minute social crowding stressor. Note the scale differences among the three panels. aP < 0.05 vs. respective paired value; bP < 0.05 vs. respective pre-stressor value. SDNN, standard deviation of normal-to-normal intervals; RSA, respiratory sinus arrhythmia.