Fluids and barriers of the CNS: a historical viewpoint

Abstract

Tracing the exact origins of modern science can be a difficult but rewarding pursuit. It is possible for the astute reader to follow the background of any subject through the many important surviving texts from the classical and ancient world. While empirical investigations have been described by many since the time of Aristotle and scientific methods have been employed since the Middle Ages, the beginnings of modern science are generally accepted to have originated during the 'scientific revolution' of the 16th and 17th centuries in Europe. The scientific method is so fundamental to modern science that some philosophers consider earlier investigations as 'pre-science'. Notwithstanding this, the insight that can be gained from the study of the beginnings of a subject can prove important in the understanding of work more recently completed. As this journal undergoes an expansion in focus and nomenclature from cerebrospinal fluid (CSF) into all barriers of the central nervous system (CNS), this review traces the history of both the blood-CSF and blood-brain barriers from as early as it was possible to find references, to the time when modern concepts were established at the beginning of the 20th century.

Circumventing the blood–brain barrier

“…But Ehrlich's student Edwin Goldmann later managed to stain the brain by injecting dye directly into the cerebrospinal fluid. Together, the findings suggested the brain was somehow protected from general circulation (1,2).…”

“…Direct evidence for such a barrier, however, would await the rise of the electron microscope in the 1950s and 60s, which ultimately revealed that strands of proteins joined together the endothelial cells lining the brain's vasculature, walling off passing molecules. These so-called "tight junctions" are also found elsewhere in the circulatory system, but they are especially tight in the brain, restricting flow down to 10-15 angstroms (1,2).…”

Functional and Genetic Analysis of Choroid Plexus Development in Zebrafish

“…To date, four CNS barriers have been described (Liddelow, 2011); three of which are represented in Figure 1-1. The most studied is the blood brain barrier (BBB) which is comprised mainly of endothelial cells that express tight junction and transporter proteins to create a barrier between blood and brain tissue.…”

Lina Stern (1878–1968): an outstanding scientist of her time

“…In 1918, a new department BPhysiological Chemistry^was established at the University of Geneva, and Dr. Stern became a chaired Professor of the department. She was the first woman to receive the rank of Professor at the University of Geneva [1,6,7].…”