Josie Clarkson is a South London dementia adviser and science writer. Here she tells us more about star-shaped cells in the brain and what part they have to play in dementia.
What are astrocytes?
You may be familiar with astrocytes from our previous article ‘Stars of the show’.
Astrocytes are star-shaped cells in the brain that help to clear away waste products, helping neighbouring brain cells to work properly.
Recent research suggests that how acidic these astrocytes are could make a difference to their role in the development of Alzheimer’s disease.
Clusters of a protein called amyloid are found in the brains of people with Alzheimer’s. Amyloid disrupts the communication between brain cells. As brain cells die, this causes a gradual and progressive decline in the person’s memory and thinking skills.
Acidic astrocytes can't clean up
In healthy brains, astrocytes ‘mop up’ amyloid before it can do any damage. However, if astrocytes are too acidic or alkaline, then astrocytes can’t take hold of the amyloid and so it doesn’t get cleared up. That means the amyloid can build up in the brain.
New research by Professor Hari Prasad and Dr Rajini Rao found that the astrocytes of people with Alzheimer’s disease are more acidic than those of other people’s. In people with Alzheimer’s, the researchers also discovered faults in genes that control the acidity of their astrocytes.
Can we fix it?
Not satisfied with simply understanding astrocyte acidity, the researchers also wanted to fix it. They treated mice, which had been bred to develop Alzheimer’s, to change the genes that control astrocyte acidity.
They also treated them with an antibiotic, which they also expected to reduce the acidity of their astrocytes. Both of these treatments made the astrocytes less acidic, and this allowed them to clear the amyloid. This, in turn, boosted the mice’s thinking and memory skills.
Professor Prasad and Dr Rao have brought astrocyte acidity into the spotlight. In the future, research could investigate whether astrocytes hold the key for potential treatments.