Reflex responses of single renal sympathetic fibres to stimulation of atrial receptors and carotid baro- and chemoreceptors.

Recordings were made of the discharge of single fibres from renal sympathetic efferent nerves in the anaesthetized dog. Stimulation of left atrial receptors by distension of small balloons at the junctions of the pulmonary veins and the left atrium resulted in a reduction in the discharge of one group of these single fibres and no change in the discharge of a second group of fibres. Bilateral occlusion of the common carotid arteries resulted in an increase in the discharge of all single fibres tested. All fibres tested which responded to stimulation of atrial receptors also responded to carotid occlusion. These results provide evidence for convergence of the central pathways from atrial receptors and baroreceptors on individual sympathetic efferent neurones.