Supraspinal control of reflex activity in renal nerves.

1. In anaesthetized cats distension of carotid sinus inhibited renal nerve activity and intercostal-renal nerve reflexes. The degree of inhibition was dependent on the amount of rise in sinus pressure. Intercostal-intercostal reflexes were not inhibited.2. Inhibition of renal nerve activity and intercostal-renal nerve reflexes could be obtained on stimulating in the dorsal reticular formation but mainly in the ventromedial reticular formation at the level of the obex. The intercostal reflex could also be inhibited at several of these points.3. The possibility that two inhibitory mechanisms are available is suggested, at least one projecting on to spinal reflex arcs.4. Other ways of inhibiting renal nerve activity were shown. One was similar to that produced by single shocks to peripheral skin and muscle nerves, and the other was due to a subnormal excitability of vasomotor neurones following intense activation.