Fig. 2

Heart rate changes elicited by acupuncture-like stimulation of a hindlimb during hypercapnia. a Sample responses of heart rate. b Summary of basal heart rate during hypercapnia. c, d Summary of responses of heart rate. c Changes in heart rate at the end of the acupuncture-like stimulation were compared with pre-stimulus basal values and plotted as absolute values. d Heart rate responses under control conditions \( (F_{{{\text{ET}_{\text{CO}}}_{ 2}}} 3.0\% ) \) were taken as 100%. Each point or column and vertical bar depicts the mean ± SEM for 5 rats. Other details are the same as in Fig. 1