In this book, leading experts in the field review how circadian rhythms impact the brain. An essential function of mammalian life is the exploitation of the regularities provided by the 24-hour cycle of day and night. The development and evolution of circadian clock mechanisms have allowed us to optimally adapt our behavior and physiology to the external world. Not surprisingly, a growing body of evidence links the disruption of circadian rhythms by genetic, lifestyle and environmental factors to illnesses of the brain. In the first section of the book, readers will learn about the molecular and anatomic architecture of circadian function in mammals. The ways in which environmental disruptions and misalignments can influence such mechanisms and therefore impair brain function and health status are also addressed. In the second part, the focus shifts to those brain regions responsible for brain function and the body-wide regulation of circadian function.