New vessels discovered: Vessels Link Brain Immune System
Published: June 6, 2015
New vessels discovered: Vessels Link Brain Immune System, Scientists have discovered a previously unknown link between the brain and the immune system that could help explain links between poor physical health and brain disorders including Alzheimer’s and depression.
The discovery of vessels, nestled just beneath the skull, overturns decades of textbook teaching and could pave the way for new approaches to treating brain diseases. The scientists behind the discovery described their surprise at having uncovered a major anatomical structure that until now had been entirely overlooked.
“These vessels were just not supposed to be there based on what we know,” said Jonathan Kipnis, who led the work at the University of Virginia. “I thought the body was mapped and that these discoveries ended somewhere around the middle of the last century. But apparently they have not.”
The finding could provide a firm biological basis for growing evidence that mental health and the state of the immune system are closely intertwined.
People with diabetes, an auto-immune disease, are 65% more likely to develop dementia, a study early this year revealed. Other recent research showed that Alzheimer’s patients who suffered regular infections, such as coughs and colds, had a fourfold greater decline in memory tests during a six-month period compared with patients with the lowest infection levels.
However, it has not been clear whether the findings had real physiological underpinnings or whether they simply reflected lifestyle factors, such as diet and sedentary lifestyles, that degraded both mental and physical health independently.
“We believe that for every neurological disease that has an immune component to it, these vessels may play a major role,” said Kipnis. “In Alzheimer’s, there are accumulations of big protein chunks in the brain. We think they may be accumulating in the brain because they’re not being efficiently removed by these vessels.”
A condition like diabetes, he added, which impacts the immune system throughout the body, could also be impairing the brain’s ability to clear away the toxic proteins that are the hallmarks of the disease. The precise role of the vessels, the scientists said, remains speculation at this stage, and putting these questions to the test will be the focus of the next phase of their research.
The new anatomy is an extension of the lymphatic system, a network of vessels that runs in parallel to the body’s vasculature, carrying immune cells rather than blood. Rather than stopping at the base of the skull, the vessels were discovered to extend throughout the meninges, a membrane that envelops the brain and the spinal cord. The vessels were probably overlooked, Kipnis said, because the meninges is often regarded as the brain’s shrink-wrap packaging, rather than a piece of anatomy in its own right.
“In your medical handbook as a student, the first instruction is ‘remove meninges’,” he said. “People aren’t that interested in this area of the brain.”.
The discovery came after the scientists developed a way to mount a mouse’s meninges on a single slide so that it could be examined as a whole. After noticing vessel-like patterns in the distribution of immune cells on the slides under the microscope, they embarked on a series of tests which proved they were looking at lymphatic vessels that served the cerebral spinal fluid, the liquid that cushions the brain and spinal cord.
Preliminary experiments suggest the same anatomy exists in people, according to the research published this week in the journal Nature.
“We’re pretty confident that they’re there in humans as well,” said Kipnis.
Please feel free to send if you have any questions regarding this post , you can contact on