Brain Aging: Models, Methods, and Mechanisms PDF

Preface

Studies of brain aging have certainly (dare we say it) come of age. The past two to three decades produced a striking increase in experimental investigations of the neurobiological basis of brain aging and of aging-related changes in neural and cognitive function. The public's interest in experimental gerontology has grown as the public has become more "gray," with both average age and life expectancy increasing in most developed countries. Driving the specific interest in the aging nervous system is the recognition that increased longevity has little appeal for most unless it is accompanied by maintenance of cognitive abilities. Indeed, if one searches the popular press or the Internet for information on aging, or for products that are purported to slow the aging process or limit its effects, one concludes that maintaining brain function may be the most important concern of older individuals. In recent years, neuroscientists with a variety of training and experimental approaches have joined established investigators of brain aging in developing increasingly powerful and quantitative methods. New animal model systems have been developed and old ones have become better characterized and standardized. In addition, advances in brain imaging techniques now permit investigations in aging humans with amazing resolution and sophistication, and also provide a bridge between human and animal studies. The (necessary and important) descriptive studies that dominated the field in earlier times increasingly are supplemented by more hypothesis-driven research, resulting in sophisticated investigations and models of the mechanisms of brain aging.

This volume provides an overview — an admittedly selective overview — of current research on brain aging. In presenting the most important and novel investigations in their areas of expertise, the contributors were asked to discuss not only data and mechanisms, but also the models and methods that are important in their work. The chapters do not include detailed experimental protocols, but each contains extensive references and highlights experimental concerns that are magnified or unique in studies of the aging brain. Readers will observe that many contributors note common challenges. Aging, some say, is not for wimps, and neither are aging studies. Investigating what happens to the brain in the latter part of the lifespan brings with it unique difficulties. For example, simply obtaining healthy individuals with known life histories at appropriate ages can be challenging (aging may be one of few areas of biomedical research in which good human subjects are arguably easier to obtain than appropriate experimental animals). It is critical to differentiate effects of aging from effects of aging-related disease; and even in the absence of ongoing disease, pathophysiological or developmental processes that occurred years or decades earlier may profoundly affect how an individual ages. This volume neither addresses all the critical experimental questions about the aging brain nor does it provide solutions to all the challenges inherent in such studies, but it should leave the reader with a broad and reasonably deep understanding of both recent progress and the future in this important field.

At this point I would like to express my sincere thanks to the many contributors to these chapters and to this volume. I have enjoyed excellent and friendly support from CRC Press staff, particularly David Fausel and Barbara Norwitz. Thanks to Series Editors Sidney Simon and Miguel Nicolelis for the invitation to undertake this project. Finally, I would like to thank Jesse Lichstein for her help in getting this book together for publication.