Vascular channels connect skull bone marrow to brain surface

White blood cells such as neutrophils may defend against infection, but they also have destructive properties. The production of white blood cells in bone marrow -- soft, sponge-like tissue in the center of most bones -- often contributes to tissue damage and impaired organ function. For example, neutrophils are linked to poor neurological outcomes after stroke. A recent study in mouse models of stroke and meningitis -- inflammation (swelling) of the protective membranes covering the brain and spinal cord – showed that neutrophils derived from skull bone marrow take an unexpected shortcut, migrating toward adjacent inflamed brain tissue through microscopic vascular channels. Because inflammation plays a critical role in many brain disorders, it is possible that the newly discovered channels may be important in a number of conditions. Future research will seek to identify the other types of cells that travel through the tunnels and the role these structures play in health and disease. The study, which was partly funded by the NHLBI, was published in the journal Nature Neuroscience.