New research has identified how much time it takes for brain neurons to die after a traumatic brain injury (TBI).
The study, published in the journal Scientific Reports by researchers at Brown University, found a way to monitor how long brain cells have to live after undergoing trauma, helping medical professionals understand what TBI looks like at the cellular level and how it can be treated.
To complete the study, the researchers used a custom-built laboratory device that can compress neurons inside 3D cell cultures while using a microscope to continuously monitor changes in cell structure.
They grew rat neurons in 3D collagen cultures and then used the device to deliver compressive forces to the culture, simultaneously studying images of the cell structure through a microscope, allowing the scientists to observe the effects in real time.
"This is the first study that applied this kind of strain to brain cells and followed them over time," said Christian Franck, one of the authors on the study and an assistant professor in Brown's School of Engineering, in a statement. "We're excited because we can finally get some concrete information about when cells start to degenerate, when they die and what the process looks like."
The study found that after a compression event with trauma forces to the head, it takes about six hours for neurons to develop irreparable structural damage, suggesting there may be a window for intervention that could help save neurons and even lives. But the severity of the trauma dictates exactly how long a cell has to live before it dies.
In the study, cells that were exposed to a 7 percent strain died after about 12 hours, while those exposed to a 12 percent strain died after about seven hours.
Additionally, the study found that two types of structural damage occur in cells when a blunt force hits the head. The first type, which is called diffuse axonal injury, is well-known as a hallmark manifestation of cellular TBI. The second form, which can also lead to cell death, has not been associated with these type of injuries, suggesting that the full extent of TBI damage could be underestimated in some cases.
"Our system doesn't have nearly the complexity of a real brain, so we're not saying that it plays out exactly this way in traumatic brain injury patients," Franck said. "But we wanted to start simply and get fundamental data on how neurons respond to these strains. We think it provides a good starting point for further research."