23 November 2017
The aging brain
Published online 24 January 2017
Highlighting the link between aging, and changes to cell-type-specific genes.
Neurobiologists are yet to provide a comprehensive picture on how neurodegeneration, which inevitably destroys nerve cells, is linked to aging. But a new research that describes how aging significantly affects glial cells, the supporting brain cells that surround and insulate neurons, is a step closer to understanding this relationship1.
“Glial cells could be a promising target for therapies aimed to slow down the progression of age-related brain disorders,” says lead scientist Jernej Ule from University College London, UK.
Examining postmortem brain samples from 480 individuals aged between 16 and 106, neurobiologists from the UK and Saudi Arabia detected age-related genetic changes in 10 different brain regions. These changes affected glial cells, especially those located in the hippocampus, the seat of memory, and substantia nigra, which controls movements — brain regions that are specifically affected in cases of Alzheimer’s and Parkinson’s disease.
Besides a significant decrease in the number of oligodendrocytes, a type of glial cells that insulate neurons, the numbers of some the largest neurons in the brain cortex dwindled.
In an adult brain, glial cells usually keep dividing whereas neurons are rarely replaced, suggesting that it is easier to regenerate glial cells, the researchers say. The interactions between glial cells and neurons also play important roles in brain function. These interactions are a promising target for therapies, says Ule.
- Soreq, L. et al. Major shifts in glial regional identity are a transcriptional hallmark of human brain aging. Cell Reports. 18, 557–570 (2017).