It is reported that a previously unknown, new anatomical structure is found inside the brain.
The newly discovered membrane was first identified in mice, but has since been observed in the adult human brain as well. It’s only a few cells thick and one of the four membranes between the skull and the brain. The other three collectively make up the meningeal layer. The latest discovery divides the space below the arachnoid layer, which contains cerebrospinal fluid (CSF) and called the subarachnoid space.
In doing so, it fuses other meningeal membranes to form a barrier between the brain and the rest of the body. In particular it seems to separate newly made (clean) cells from old (dirty) cells. Therefore, it is likely to be involved in the glyphatic system, a network responsible for removing waste from the brain.
Maiken Nedergaard, one of the authors of the study announcing the discovery, said in a statement: “The discovery of a new anatomical structure that separates and helps control the flow of cerebrospinal fluid (CSF) in and around the brain now adds to the complex role that CSF plays in the transport and removal of waste from the brain. It also shows that it helps to support the immune defense at the same time,” he said.
The new discovery is thought to have implications for the study of brain injuries and diseases such as multiple sclerosis and Alzheimer’s.
The researchers say they noticed that the number and diversity of immune cells in SLYM increases with inflammation and aging. They also suggest: “Physical rupture of the SLYM may alter CSF flow patterns, explaining the long-term suppression of glyphatic flow and a high risk of developing post-traumatic Alzheimer’s disease as well as traumatic brain injury.”
In short, this new structure may be affecting a range of brain conditions, and the researchers hope its discovery will help us better understand them.