Located at the interface between blood and the brain, the blood-brain barrier is a dynamic permeability barrier formed by a continuous layer of specialized endothelial cells endowed with important permeability, transport, and regulatory functions that both protect the internal milieu of the brain and allow essential nutrients to be transported into the brain. Over the last 25 years, we have witnessed remarkable expansion of our knowledge of the structure, biology, and function of the cerebral endothelium. In The Blood-Brain Barrier in Health and Disease, Volume 1, international experts discuss basic and new concepts and most recent advances pertaining to the development of the cerebral microvascular system. Subjects include the structure, function, permeability properties, transport mechanisms, and the inherent heterogeneity of the cerebral endothelium; the anatomy and physiological properties of the neurovascular unit; functional aspects of the choroid plexus; and important concepts and advances made over the last two decades that have shaped our understanding of the immunological function of the blood-brain barrier. This book is intended to serve as a valuable source of basic and advanced information for researchers, students, and clinicians interested in this fast-expanding field and stimulate further research well into the future.