Could we slow down the consequences of aging in the brain?

The human brain is one of the first victims to suffer the ravages of the passage of time. As we age, our brain reduces its weight and size by up to 15% , causing a deterioration in cognitive functions, memory and learning capacity . Brain aging is also associated with neurodegenerative diseases, memory loss or dementia. New research indicates that the development of these diseases, such as Alzheimer’s , or the decline in cognitive ability caused by the passage of time are related to the aging of the vessels that connect the brain and the immune system .

The team from the University of Virginia School of Medicine , by delving into this connection, has managed to significantly increase the ability to learn and remember in elderly mice after improving the functioning of their lymphatic vessels . If this line of research were to continue, new ways to treat or prevent Alzheimer’s disease, age-associated memory loss, and other neurodegenerative diseases could be developed. The research leader is Dr. Jonathan Kipnis , the neuroscientist responsible for the 2015 discovery of the lymphatic vessels that surround the brain. Despite the relevance that this fact had, Kipnis has declared that his latest study is the most important to date. “When you get naturally aged mice to learn and remember it is very exciting,” he said. ” We are very optimistic about the possibility of living many years without developing diseases such as Alzheimer’s .”

The brain cleansing process

The lymphatic vessels of the brain, which were not believed to exist until their discovery, appear to play a very important role in the brain’s self-cleaning process . The work carried out by the researchers provides the most complete vision that is available to date of the purpose of these vessels and their contribution to the proper functioning of the brain and its aging.

Kipnis, director of the Center for Brain Immunology and Glia (BIG), and his team used a compound that increased the flow of waste from the brain to lymph nodes in the neck in aged mice. These, as part of the immune system, filtered and drained waste substances from the brain, and this improved function had a direct effect on the mice’s ability to learn and remember . This was the first time that the cognitive abilities of mice have been enhanced through the lymphatic vasculature that surrounds the brain. The results obtained indicate that the obstruction of the vessels in mice caused the accumulation of harmful amyloid plaques , which are usually related to Alzheimer’s and whose accumulation has not yet been explained.

“If we talk about people with Alzheimer’s, 98% of the cases are not caused by a family predisposition, so it would be important to know what aspects of the brain are affected and cause these diseases,” said researcher Sandro Da Mesquita . The team’s next step is to find out what changes occur in the aging human brain in order to develop a specific treatment for aging-related diseases.

Treat or prevent

The Kipnis team aims to develop a drug that improves the functioning of the lymphatic vessels and they point out the importance of developing a method that allows determining how the meningeal lymphatic vasculature works in people. They affirm that the best way to treat Alzheimer’s disease is to combine the repair of the lymphatic vasculature with other processes, and even that this new information could lead to a return to previous treatments that had been discarded. “Reversing Alzheimer’s will be difficult, but perhaps we can delay its symptoms while maintaining the functionality of the lymphatic vasculature,” concludes Kipnis.

Referencia: Sandro Da Mesquita, Jonathan Kipnis & team. ‘Functional aspects of meningeal lymphatics in ageing in Alzheimer’s disease’. Nature (2018). DOI: https://doi.org/10.1038/s41586-018-0368-8