📖 The monograph provides convincing evidence that mammals have serotonergic nerves. Serotonergic nerve is a collective term (as well as sympathetic nerve). Sympathetic trunks, their ramifications and branches innervate the internal organs. There are several times more serotonergic fibers in the sympathetic trunk than the adrenergic ones. Electrical stimulation of the sympathetic trunk in the thoracic cavity of dogs mostly increases motility of the stomach and duodenum but not inhibit it. For teachers, researchers and graduate students.