[Interaction of abdominal vagus and greater splanchnic nerve activities in the nucleus tractus solitarius of the rabbit].

Experiments were performed on 67 rabbits. Effects of stimulation of the central ends of abdominal vagus and greater splanchnic nerve on arterial blood pressure before and after destruction of nucleus tractus solitarius (NTS) and the unit discharges in the NTS before destruction were observed. As a result, we suggest that both the afferents coming from the abdominal vagus and greater splanchnic nerve not only converge on NTS neurons but also interact with each other. Subthreshold stimulation elicited from one of the afferent fibers suppresses the arterial blood pressure responses caused by the other afferent. Similarly, background stimulation elicited from one afferent can suppress the NTS unit discharges caused by the other afferent. It is much easier for abdominal vagal afferent to inhibit the NTS unit discharges and the arterial blood pressure changes elicited by stimulation of the splanchnic nerve. A possible mechanism of such relationship was discussed.