Cerebrovascular heterogeneity and neuronal excitability.

The cerebral vasculature is a complex tridimensional network of arterial and venous vessels which are anatomically in proximity of and functionally coupled to neurons. Depending on the cellular composition of the vascular wall and size, cerebral vessels control regional blood flow, define interstitial homeostasis or cerebrospinal fluid circulation and influence immune cell patrolling. Pathological deviations from these functions promote or are a consequence of brain diseases, directly impacting neuronal firing. We propose that specific cerebrovascular segments are differentially implicated in the pathophysiology of epilepsy, including difference between white and grey matter. We offer plasticity of perivascular mural cells and endothelial-pericyte interactions as emerging players. We outline the potential for MRI vascular biomarkers tailored to the epileptic brain, specifically cerebral blood volume and flow, tissue oxygen saturation and microvessel permeability. Finally, we show the advantages of the guinea pig whole brain preparation to study the link between cerebrovascular permeability, expression of vascular adhesion molecules, inflammation and neuronal excitability.