Blood-Brain Barrier Dysfunction in Epileptogenesis

The blood–brain barrier (BBB) is a specialised multicellular interface that tightly regulates the exchange of ions, molecules and cells between the blood and the central nervous system. In healthy brain tissue, endothelial cells linked by tight junctions, supported by pericytes and astrocytic end-feet, maintain a stable microenvironment essential for neuronal function. Disruption of BBB integrity—through injury, inflammation or sustained hyperexcitability—permits serum proteins such as albumin to enter the parenchyma, triggering astrocyte activation, cytokine release and extracellular matrix remodelling. These events promote synaptic reorganisation, neuroinflammation and network hyperexcitability, thereby lowering seizure threshold and contributing to epileptogenesis. Emerging evidence indicates that subtle changes in tight junction composition, basement membrane structure and neurovascular coupling occur during a latent period preceding overt seizures. Therapeutic strategies aimed at restoring BBB stability, modulating inflammatory cascades and preserving vascular–glial interactions are increasingly viewed as a means to prevent or attenuate the development of epilepsy.

Research from Nature Portfolio

Recent studies have elucidated molecular drivers of barrier disruption and identified targets for stabilisation. One investigation revealed that selective loss of the tight junction protein claudin-5 in human epileptic tissue and in experimental models correlates with enhanced permeability and worsened seizure phenotypes. Genetic or focal knockdown of claudin-5 precipitated spontaneous recurrent seizures and severe neuroinflammation, whereas pharmacological upregulation of claudin-5 expression prevented seizure activity. Another seminal work demonstrated that extravasation of serum albumin into brain tissue activates transforming growth factor-β (TGFβ) signalling in astrocytes, leading to degradation of protective perineuronal nets around inhibitory interneurons. This extracellular matrix remodelling disrupts inhibitory circuitry and predisposes to chronic network hyperexcitability following injury. Together, these findings underscore the central role of tight junction integrity and astrocyte-mediated inflammatory pathways in early epileptogenic processes.

Blood-Brain Barrier Dysfunction in Epileptogenesis publication trend

The graph below shows the total number of articles in blood-brain barrier dysfunction in epileptogenesis across all publications each year (not limited to Nature Index journals).

Technical terms

Blood–brain barrier (BBB): A selective vascular interface formed by endothelial cells, tight junctions, pericytes and astrocytes that regulates molecular and cellular traffic into the central nervous system.

Epileptogenesis: The gradual process by which a normal brain develops epilepsy, involving molecular, cellular and network changes leading to spontaneous seizure activity.

Tight junctions: Protein complexes between endothelial cells that seal intercellular clefts and restrict paracellular diffusion of solutes and cells.

Neurovascular unit (NVU): The functional ensemble of endothelial cells, pericytes, astrocytes, neurons and extracellular matrix that cooperatively maintains cerebral blood flow and barrier integrity.

Perineuronal nets (PNNs): Specialized extracellular matrix structures surrounding certain neurons that stabilise synapses and regulate plasticity.

Claudin-5: A transmembrane tight junction protein predominantly expressed in brain endothelium, crucial for size-selectivity and barrier impermeability.

References

1. Microangiopathy in temporal lobe epilepsy with diffusion MRI alterations and cognitive decline. Acta Neuropathologica (2024).
2. Sex differences in physiological response to increased neuronal excitability in a knockin mouse model of pediatric epilepsy. Clinical Science (2024).
3. Structural, Molecular, and Functional Alterations of the Blood-Brain Barrier during Epileptogenesis and Epilepsy: A Cause, Consequence, or Both?. International Journal of Molecular Sciences (2020).
4. TGFβ signaling is associated with changes in inflammatory gene expression and perineuronal net degradation around inhibitory neurons following various neurological insults. Scientific Reports (2017).
5. Microvascular stabilization via blood-brain barrier regulation prevents seizure activity. Nature Communications (2022).
6. Blood–Brain Barrier Leakage during Early Epileptogenesis Is Associated with Rapid Remodeling of the Neurovascular Unit. eNeuro (2018).
7. The Roof is Leaking and a Storm is Raging: Repairing the Blood–Brain Barrier in the Fight Against Epilepsy. Epilepsy Currents (2019).