Brain Injury Can Cause Rebound Effects

Brain cells can cause a chain reaction when there is an injury, that stops activity across a vast network of neural circuits, according to new research from Oregon Health & Science University, published in the journal Neuron. "Even the so-called bystander neurons that aren't injured or diseased can sense there's been an injury and radically change their function. That means that it's not just the broken neurons that are affected when you have a nervous system injury - it's maybe all of the neurons", said senior author Marc Freeman, Ph.D., director of the Vollum Institute at OHSU.

This describes the reason why traumatic brain injury or disease results in temporary but severe loss of cognitive function.

The bystander effect :

Research on the fruit fly Drosophila demonstrated that the relatively minimal injury to a small number of axons in a larger bundle rippled out beyond the severed axons. This also suppressed the sensory signals among neurons that weren't directly damaged.

This bystander effect was attributed to response to glial cells, the abundant but oftentimes overlooked supporting cell within the brain. The study suggests that this brain response helps in conserving large amounts of energy following a disease or injury, which is revived after the injury clears.

"Our best guess is that it allows the nervous system to pause after an injury. It enables cells to assess their status and, if they're not healthy, activate programs to destroy themselves. If they're healthy, they recover", says Freeman.

Source-Medindia