Serotonin: The Mediator That Spans Evolution provides a comprehensive review of the widespread roles for serotonin in respiratory, cardiovascular and thermoregulatory control, and for growth and development in early life. This important resource highlights serotonin's role in normal (unstressed) conditions, and in response to a variety of physiological stressors. It focuses on new animal models, comparing and contrasting data from mice and rats. In addition, the book compares and contrasts the physiological effects of brain and blood serotonin systems and includes new data suggesting that the influence of serotonin is in part through the regulation of gene expression. Finally, it discusses the role of serotonin system dysfunction in a variety of pathophysiological conditions, including sleep apnea, obesity and hypertension, and presents compelling evidence that this dysfunction is involved in Sudden Infant Death Syndrome (SIDS).