The aging process involves changes in neurotransmission at different levels. The purpose of this book is to help define the state-of-the-art of the field and to give directives for future research on the aging brain. Following topics are presented: the comparison of normal and pathological aging at the anatomical and neurochemical level; the knowledge of the responses of the aging brain to drug treatment or environmental stress; the neuro/immune and neuro/endocrine setting during aging; and the definition of therapeutical approaches in normal aging. This book will interest physicians and pathologists as well as neurophysiologists.