The blood-brain barrier in vitro: the second decade

Area of Science:

• Neuroscience
• Cell Biology
• Physiology

Background:

• The blood-brain barrier (BBB) is a critical interface regulating molecular traffic between the blood and the central nervous system (CNS).
• Endothelial cells of the CNS form the structural basis of this unique barrier, controlling the passage of essential nutrients, hormones, and drugs.
• Understanding the BBB's properties has been a long-standing goal since Ehrlich's initial discovery of restricted material exchange.

Purpose of the Study:

• To review advancements in understanding the blood-brain barrier (BBB).
• To highlight the significance of in vitro models for studying cerebral endothelial cells (CEC).
• To summarize findings from isolated brain microvessel studies over the past decade.

Main Methods:

• In vivo studies using endogenous and exogenous tracers to assess BBB permeability.
• Development and utilization of in vitro blood-brain barrier (BBB) model systems since 1973.
• Analysis of isolated brain microvessels to investigate CEC properties and function.

Main Results:

• Cerebral endothelial cells (CEC) are now recognized as the primary cellular component responsible for the BBB's barrier function in vertebrates.
• In vitro BBB models have significantly contributed to understanding the unique permeability characteristics of CEC.
• Studies on isolated brain microvessels have provided valuable insights into BBB mechanisms.

Conclusions:

• In vitro models represent a powerful tool for dissecting the complex physiology of the blood-brain barrier (BBB).
• Continued research using these models is essential for advancing our knowledge of cerebral endothelial cell (CEC) function.
• The findings underscore the importance of CEC in maintaining CNS homeostasis and offer potential for therapeutic interventions.