Synergistic effect of serotoninergic and cholinergic nerve fibers

The mechanisms of interactions between various compartments of the autonomic nervous system were evaluated by studying sympathetic potentiation of vagal cardioinhibitory action. It was found that this effect is realized through preganglionic serotoninergic nerve fibers making synaptic contacts with intracardiac serotoninergic neurons. Our results indicate that cardiac activity is modulated by the vagus nerve and serotoninergic nerve fibers of the sympathetic nerve acting synergistically.