Fig. 5. Absolute changes in heart rate variability (HRV) frequency bandwidth, in control animals and in animals after incubation with (A) propranolol (ß-adrenergic antagonist, 10^–5 mol l^–1) and atropine (muscarinergic antagonist; 10^–5 mol l^–1) or (B) with each agonist separately. Asterisks indicate statistically significant differences between incubated and control animals (P<0.05). N=7 (per stage).