Facilitation, occlusion and conditioning of pressure responses evoked by developing during aortic nerve stimulation in rabbits.

In the experiments on rabbits the reactions of arterial pressure fall during unilateral and bilateral simultaneous stimulation of the aortic nerve and during conditioning of arterial pressure change effects preceding stimulation of the same nerve, contralateral aortic nerve, vagal afferents and tibial nerve were investigated under general anaesthesia with urethane. The main effect of simultaneous stimulation of both aortic nerves was occlusion. Facilitation developed in a very narrow range of stimulation intensities used. The results of conditioning of depressor response pressure fall reaction obtained from the aortic nerve using various afferent fibres point to differences in the degree of utilization of common interneuronal pathways stimulated in both these ways.