Hormonal Responses During Neurally Mediated Syncope as an Indication of Central Serotonergic Activity

mediated syncope (NMS) is not well known. Both peripheral (Bezold-Jarish reflex) and central nervous system (CNS) activation have been proposed to explain the paradoxical activation of the inhibitory cardiac vagal afferent neuronal activity and withdrawal of the sympathetic activity that occurs during NMS. Among the latter, central serotonergic mechanisms have been received little attention. By the early 1990’s a lot of research work was published on the participation of serotonin (5-hydroxytryptamine (5HT)) of the CNS in the cardiovascular homeostasis and provocation of the NMS. Application of serotonin directly