Science Alert reports:

A shortcut between the skull and the brain could be a possible way for the human immune system to bypass the blood-brain barrier.

Researchers recently discovered a series of tiny channels in mice and human skulls, and in mice at least, these little pathways represent an unexpected source of brain immunity.

Previously, scientists assumed that the immune system connects with the brain by slipping through a kind of neurological customs gate – a barrier separating blood channels from important neural tissue.

Now it seems there’s no need to go the long way around after all. Immune cells inside the very bone that surrounds the brain appear to have a more direct path.

Last year, researchers found a whole host of immune cells hidden in the bone marrow of the mouse cranium. When confronted with a virus or tumor in the brain, these cells traveled through the skull channels and into the cerebrospinal fluid.

Now, it seems that this secret path is actually a two-way street.

Not only can immune cells in the skull cap flow to the brain, researchers found that cerebrospinal fluid can also seep through to the skull.

Experts think it works sort of like an immune pit stop. [Continue reading…]