FUNCTIONAL-SIGNIFICANCE OF THE 10 HZ RHYTHMIC DISCHARGES IN SYMPATHETIC-NERVES

1. By measuring renal vascular conductance in anaesthetized and immobo lized rabbits, the functional significance of the 10Hz rhythmic discha rges in the sympathetic nerves was assessed by electrical stimulation of the renal nerve. This stimulation mimicked the intermittently occur ring 10Hz rhythmic discharges. 2. Comparison of high-frequency (10-20H z) intermittent electrical stimulation with continuous low-frequency ( 5Hz) stimulation showed that the intermittent high-frequency stimulati on evoked faster (smaller time constant) and larger responses of the r enal vascular conductance if the total number of stimulus pulses was t he same, 3. Therefore, the intermittently occurring 10Hz rhythmic disc harges in the sympathetic nerve produces faster and larger effects on peripheral organs than effects produced by continuous discharges if th e number of spikes is equal.