Secret Tunnels Between Skull and Brain

Did you know you have tiny tunnels in your head? That's OK, no one else did either until recently! But that's exactly what a team of medical researchers confirmed in mice and humans in 2018 – tiny channels that connect skull bone marrow to the lining of the brain.

The research shows they may provide a direct route for immune cells to rush from the marrow into the brain in the event of damage.

Previously, scientists had thought immune cells were transported via the bloodstream from other parts of the body to deal with brain inflammation following a stroke, injury, or brain disorder.  This discovery suggests these cells have had a shortcut all along.

The tiny tunnels were uncovered when a team of researchers set out to learn whether immune cells delivered to the brain following a stroke or meningitis originated from the skull, or the larger of the two bones in the shin – the tibia.

The specific immune cells they followed were neutrophils, the "first responders" of the immune squad. When something goes awry, these are among the first cells the body sends to the site to help mitigate whatever is causing the inflammation.

The team developed a technique to tag cells with fluorescent membrane dyes that act as cell trackers. They treated these cells with the dyes, and injected them into bone marrow sites in mice. Red-tagged cells were injected into the skull, and green-tagged cells into the tibia.    READ MORE...