New study unlocks the mystery of how âRSS Feed
A German study has solved a major mystery about how specialised microglia cells “know” how to respond to a brain injury, ScienceDaily.com reports.
Microglia rush to the site of a brain injury where they scavenge away dead debris and damaged neurons. However, just how they detect where the injury is has remained shrouded in mystery.
Lead author Dr Francesca Peri said: “Considering that they help keep our brain healthy, we know surprisingly little about microglia. Now, for the first time, we've identified the mechanism that allows microglia to detect brain injury, and how that emergency call is transmitted from neuron to neuron.”
In ingenious experiments with zebrafish, Dr Peri and her team were able to track the molecular signalling system that ultimately tells the microglia where they’re needed. By inducing a focal brain injury in the fish and studying their brains under a microscope, the researchers realised that the glutamate “distress signal” emitted by damaged neurons triggers nearby neurons to absorb calcium. As they do, they release adenosine triphosphate (ATP). This is what the microglia seize on, rushing along the ATP “trail” to the damaged area.
ATP wasn’t previously thought to play a role in signalling as it breaks down rapidly after being released. It simply wouldn’t last long enough to form a trail for the microglia to follow. However, the calcium absorption by cells around the injury is the key – it functions to cause a sustained release of ATP so that it remains present for sufficient time for the microglia to follow it.
The discovery may lead to new treatments for conditions such as Alzheimer’s and Parkinson’s, where microglial signalling malfunctions.Back to Brain Injury News news