Scientists find tunnels between skull and human brain

These findings suggest that these cells can take a shortcut to reach the area of ​​inflammation quickly, said Francesca Bosetti.

Scientists reported in Nature Neuroscience the discovery of tiny tunnels that connect the marrow of the brain with the membranes that cover it, the meninges. A finding that could shed light on how the brain responds to injuries and illnesses.

We always thought that the immune cells in our arms and legs were moving through the blood to damaged brain tissue. These findings suggest that these cells can take a shortcut to reach the area of ​​inflammation quickly, said Francesca Bosetti, of the US National Institute of Neurological Disorders and Stroke, who funded the study.

Inflammation plays a critical role in several brain disorders and it is possible that the new channels described may be important in a number of these conditions.

Matthias Nahrendorf, molecular biologist at Harvard Medical School and Massachusetts General Hospital in Boston (MGH), and colleagues, discovered the channels as they tried to determine where the immune cells came from after a stroke or heart attack. In mice with a stroke, cells called neutrophils are more likely to come from the skull as found. But in mice that had had a heart attack, a similar number came from the skull and the tibia.

In the effusions, the images showed neutrophils coming out of the skull and moving through these unknown tunnels towards the damaged tissue. An analysis of samples of human skulls after surgery revealed that these channels are not unique to mice.

While we learn about them, I think their very special role as conduits for inflammation communication between the medulla and the central nervous system is very different from any other vasculature, Nahrendorf said.

In addition to these channels carrying immune cells from the marrow of the skull to the brain, we think that the inflammatory substances that are derived from the brain should alert the medulla of the skull to an injury faster than the marrow of the rest of the body, says Nahrendorf.

As inflammation is part of various brain diseases it would be important to learn how those channels contribute to these diseases and if modulating that contribution could change the results, added Nahrendorf

Another idea is that these channels could serve as a route to supply medicines, allowing transportation to the meninges of drugs placed in the marrow of the skull.