Tight junctions determine how readily substances move between adjacent brain microvascular endothelial cells. By limiting paracellular passage, they help preserve the barrier’s selective behavior, while regulated transport across the cells provides a separate route for movement. Examining these pathways helps distinguish impaired barrier integrity from changes in transport activity, an important distinction in neuroscience studies.
Brain microvascular endothelial cells provide the principal barrier-forming surface, whereas astrocytes and pericytes can be incorporated to represent additional cellular components of the barrier. Comparing endothelial-only cultures with co-culture arrangements allows investigators to examine how model complexity affects barrier properties. This choice is useful when studying disease-related disruption or interpreting compound passage in a defined system.
Permeability measurements and transendothelial electrical resistance, or TEER, provide complementary readouts of barrier integrity. Permeability testing indicates how readily substances cross the model, whereas TEER reflects the electrical resistance associated with the endothelial layer. Using these measurements gives researchers a controlled way to evaluate whether the barrier remains restrictive and compare responses across experimental conditions.
A basic workflow starts by culturing brain microvascular endothelial cells either alone or alongside astrocytes and pericytes. The selected arrangement is then examined for barrier performance with permeability measurements or TEER. This sequence lets investigators establish a defined experimental system, assess its integrity, and use the resulting model for transport, disease, or treatment-focused studies.
Researchers use this approach to characterize drug delivery and transporter activity, and to evaluate whether therapeutic compounds can reach brain tissue. Because the system provides controlled experimental conditions, investigators can examine compound passage without relying solely on animal or clinical experiments. These studies can support early assessment of brain-directed treatments and help identify delivery-related limitations.
In neuroscience, the model enables controlled investigation of barrier disruption associated with neurological disease and supports reproducible studies of neuroinflammation. Researchers can also use it to evaluate treatments designed to target the barrier itself. By linking barrier integrity measurements with disease- or treatment-focused experiments, the system helps clarify how vascular interface changes may affect therapeutic access to brain tissue.