(Telegraph) Brain has inbuilt ‘drainpipes’ which get rid of waste, scientists find
The mystery of how the brain gets rid of waste or toxic substances has finally been discovered by scientists – it has its own sewerage pipe.
For the first time, researchers have found vessels which take away harmful substances or dead cellular material to keep the brain healthy.
The findings could help scientists understand neurological diseases like Alzheimer’s which is believed to be partly caused by a build-up of sticky plaques which the brain fails to clear away.
The study also suggests that the vessels could act as a pipeline between the brain and the immune system, and could explain how physical illnesses are linked to mental problems, such as depression.
“We literally watched people’s brains drain fluid into these vessels,” said Dr Daniel Reich, senior investigator at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS).
“We hope that our results provide new insights to a variety of neurological disorders.
“For years we knew how fluid entered the brain. Now we may finally see that, like other organs in the body, brain fluid can drain out through the lymphatic system.”
The vessels discovered by the team appear to be the same as those in the lymphatic system, the body’s own sewage network which runs alongside blood vessels, clearing out waste and monitoring if the body is under attack from bacteria or a virus, or has been injured.
Until recently there was no evidence that the lymphatic system extended into the brain leading scientists to conclude it must have a different way of getting rid of waste. However studies in mice suggested a similar system may exist, so Dr Reich’s team used MRI to scan the brains of five healthy volunteers after they had been injected with a magnetic dye designed to show up the vessels.
“I was completely surprised. In medical school, we were taught that the brain has no lymphatic system,” added Dr Reich.
“These results could fundamentally change the way we think about how the brain and immune system inter-relate,” added Dr Walter Koroshetz, NINDS director.
The research was published in the journal eLife.