Alterations in sleep are common manifestations of aging that can lead to significant health problems and contribute to behavioural problems associated with age-related neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. Recent advances have revealed key cellular and molecular mechanisms involved in sleep regulation, and this knowledge is helping to advance an understanding of both the normal functions of sleep and the mechanisms responsible for abnormalities in sleep in various neurological conditions and during normal aging. This volume of Advances in Cell Aging and Gerontology brings together chapters by leaders in the fields of sleep research and the neurobiology of aging. The book starts with chapters describing fundamental aspects of the neurocircuitry involved in sleep, patterns of brain activity during the different stages of sleep and disturbances of sleep during aging. The links between depression, anxiety and insomnia are reviewed in regards to the underlying neurochemical alterations that appear to involve abnormalities in neurotransmitter and neurotrophic factor signalling. The evolutionary basis of sleep is reviewed and the emerging evidence supporting a major role for sleep in learning and memory is described. The bulk of the book focuses on specific sleep disorders associated with aging and age-related neurodegenerative disorders. A comprehensive consideration of this topic is woven through a number of chapters that address both basic research and clinical aspects of sleep abnormalities during aging and in disease. The impact of sleep on the immune system is described. The articles are written in a high level of detail and are comprehensive, thus providing valuable information for a range of scientists and other well-educated people. In particular, the book will be a valuable resource for graduate students, postdoctoral and senior scientists in the fields of sleep, aging, neurodegenerative disorders and learning and memory. In addition, clinicians will find this book valuable as it provides a bridge between basic research and the treatment of the patients with sleep disorders.