Neuronal reactivity to single stimuli applied to both the peripheral nerves and the cortex, was the same in the cat solitary tract nucleus. The 1-20 Hz stimulation frequency rendered the reactivity either tonic in character or with reduced firing rate. A high degree of convergence (80.2%) on baso-lateral nuclei neurons was established, as well as a significant cortico-fugal effect (71%) on the viscero-sensory units of these nuclei. Single shocks and tetanic stimulation of the baso-lateral amygdala evoked mostly phasic responses of the primary as well as secondary vagal neurons. Feed-back mechanisms of the amygdaloid control of the bulbar viscero-sensory units are discussed.