The Cerebral Microvasculature: Investigation of the Blood-Brain Barrier

As traced by Uichael Bradbury in his recently published monograph, The Concept of a BZood-Brain Barrier, the idea of a scientific challenge is just about as old as the twentieth century. Curiously, it remains undefined. Is it a structure or structures as some use the term, or is it a reciprocal per­ meability, a force-flow relationship, as do others, or is it a group of processes, some more specialized than others? Depend­ ing upon the observer, the method, and what is observed, it seems to...