Fig. 3. (A) Schematic drawing of the SEG. seg, segments; NR, nerve roots of SEG. (B) Effects of stimulation of the 10th, 16th and 19th NR on ECG. The roots were anatomically determined to contain, respectively, CI, CA1 or CA2 nerves. The bar shows a period of repetitive stimulation. Stimulus frequencies (Hz) are shown at the beginning of the recordings. (C) Effects of stimulations of the 10th, 16th or 19th nerve root on heart rate. Values are means ± S.D.; N=7 for 10th NR, N=9 for 16th NR, N=10 for 19th NR.