Influence of the input from left and right arterial baroreceptors on left inferior cardiac nerve activity in cats.

Input from the ipsi- and contralateral arterial baroreceptors to the left inferior cardiac nerve was tested in chloralose anaesthetized cats. The cardiac rhythmicity in sympathetic tonic activity and the response to excitation of arterial baroreceptors were examined. It was found that the inhibitory input to the left inferior cardiac nerve front ipsilateral carotid sinus baroreceptors was not different from the inhibition of sympathetic activity from the contralateral carotid sinus baroreceptors. On the contrary, the left inferior cardiac nerve was almost exclusively controlled by an inhibitory input from the ipsilateral aortic baroreceptors with little influence from the aortic baroreceptors of the contralateral side. We conclude that transmission of the information from the carotid sinus baroreceptors to the cardiac sympathetic nerves is crossed, whereas information from the aortic baroreceptors is mainly uncrossed in the central nervous system.