Perivascular spaces and the two steps to neuroinflammation

T Owens, I Bechmann… - Journal of Neuropathology …, 2008 - academic.oup.com
T Owens, I Bechmann, B Engelhardt
Journal of Neuropathology & Experimental Neurology, 2008academic.oup.com
Immune cells enter the central nervous system (CNS) from the circulation under normal
conditions for immunosurveillance and in inflammatory neurologic diseases. This review
describes the distinct anatomic features of the CNS vasculature that permit it to maintain
parenchymal homeostasis and which necessitate specific mechanisms for
neuroinflammation to occur. We review the historical evolution of the concept of the blood-
brain barrier and discuss distinctions between diffusion/transport of solutes and migration of …
Abstract
Immune cells enter the central nervous system (CNS) from the circulation under normal conditions for immunosurveillance and in inflammatory neurologic diseases. This review describes the distinct anatomic features of the CNS vasculature that permit it to maintain parenchymal homeostasis and which necessitate specific mechanisms for neuroinflammation to occur. We review the historical evolution of the concept of the blood-brain barrier and discuss distinctions between diffusion/transport of solutes and migration of cells from the blood to CNS parenchyma. The former is regulated at the level of capillaries, whereas the latter takes place in postcapillary venules. We summarize evidence that entry of immune cells into the CNS parenchyma in inflammatory conditions involves 2 differently regulated steps: transmigration of the vascular wall into the perivascular space and progression across the glia limitans into the parenchyma.
Oxford University Press