Neurovascular unit

FIGURE 11 Schematic of neurovascular unit/cell forming BBB (brain-blood barrier). (Reproduced from D. J. Begley, Pharmacology Therapeutics, 104, 29—45, 2004, with permission by Elsevier.)... 

The study recorded the medical history, medications, symptom details, examination findings, final diagnosis, treatment plans and one-year outcomes (assessed by phone calls) of all referrals. In the first report of all 629 consecutive patients with definite TIA seen from January 2003 to December 2005, there were three strokes within seven days and 12 strokes within three months of follow-up, giving risks of 0.3% and 1.9%, respectively. The expected risk of stroke at three months as calculated by the ABCD score (Johnston et al. 2007) was 6%. Although there was no formal comparison arm of the study, the considerable reduction in observed rates of stroke compared with those expected by the ABCD score was reasonably attributed to urgent access to and treatment in a dedicated specialist neurovascular unit. However, it should be noted that this study only assessed stroke risk among patients referred to the clinic and not all those within the population. 

Keywords Vasogenic edema Neurovascular unit teinases Aquaporins Blood-brain barrier Imaging... 

Normal function of the brain depends on the BBB, which provides a highly selective barrier between the blood and the brain parenchyma that creates a special microenvironment crucial for brain homeostasis. Endothelial cells, astrocytes, perivascular microglia, neurons, and pericytes comprise the neurovascular unit (Fig. 1) (Ballabh... 

Perivascular microglia make contact with cerebral microvessels and modulate the functioning of the neurovascular unit (Kaur and Ling, 2008). There are two important sources of microglia in the brain. During development, leptomeningeal mesenchymal cells enter the brain and transform into microglia (Bechmann et al.,... 

Microglia are phagocytic cells with the capability of antigen presentation. They rapidly respond to a wide variety of stimuli including inflammation and hypoxia/ischemia (Block et al., 2007 del Zoppo et al., 2007). Activated microglia release several inflammatory factors, which modulate the permeability properties of the neurovascular unit (Stoll and lander, 1999 Block et al., 2007). 

There are complex interactions among the different cellular components of the neurovascular unit and the extracellular matrix, determining its permeability properties during both physiological and pathological conditions. This highlights the severe limitations of cell culture-based models to mimic neurological diseases associated with BBB disruption. Transwell culture systems of endothelial cells alone rarely achieve adequate transendothelial electrical resistance (TEER). Cocultures of... 

Hawkins BT, Davis TP (2005) The blood-brain barrier/neurovascular unit in health and disease. Pharmacol Rev 57 173-185... 

Keywords Active transport Adsoiptive endocytosis and transcytosis Brain endothelial cell Cytokine Endothelin Facilitated diffusion Inmiune cell Neurovascular unit Trans-membrane diffusion... 

Concept of the Neurovascular Unit and Comparison to Peripheral Vascular Beds... 

The concept of the neurovascular unit (NVU) emphasizes the interactive role that cells and events wdthin the CNS and in the circulation play on BBB permeability, as w ell as the role that... 

The concept of the neurovascular unit —a funcdonal endty comprising neurons, asdocytes, smooth muscle cells and endothelial cells— has now emerged and it is appreciated that this coordinated unit plays a key role in the hemodynamic response to alteradons in brain funcdon and acdvity. Disrup-don of this regulatory network occurs after sdoke and it is now believed that efforts at neuroprotecdon should target the endre unit, not just neurons (del Zoppo, 2006). 

Elali A, Rivest S (2013) The role of ABCB1 and ABCA1 in beta-amyloid clearance at the neurovascular unit in Alzheimer s disease. Front Physiol 4 45... 

Coculture of Endothelial Cells with Other Cell Types from the Neurovascular Unit... 

Vandenhaute E, Dehouck L, Boucau MC, Sevin E, Uzbekov R, Tardivel M, Gosselet F, Fenart L, Cecchelli R, Dehouck MP (2011) Modelling the neurovascular unit and the blood-brain barrier with the unique function of pericytes. Curr Neurovasc Res 8(4) 258-269... 

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