The young brain’s hidden weakness: When plasticity goes wrong
Published on 07/09/2026 - 12:40 GMT+2 Young brains are flexible. They adapt and form new connections easily. When something goes wrong, the thinking goes, a younger brain...
Published on 07/09/2026 - 12:40 GMT+2
Young brains are flexible. They adapt and form new connections easily. When something goes wrong, the thinking goes, a younger brain has more room to reorganise itself and compensate for damage.
But that same flexibility may also have a downside after traumatic brain injury — damage to the brain caused by an external force, such as a fall, car accident, sports injury or blow to the head, according to a study published in Experimental Neurology.
“People may assume younger brains are more resilient after injury, but our findings suggest the story is much more nuanced,” said Samba Reddy, of neuroscience and experimental therapeutics at the Texas A&M Naresh K. Vashisht College of Medicine and senior author of the study.
Traumatic brain injuries affect up to 69 million people annually. Such injuries can lead to post-traumatic epilepsy, a chronic seizure disorder that can emerge months or even years after an injury.
The study suggests younger brains may be more vulnerable to the processes that lead to post-traumatic epilepsy — at least in mice.
“The same plasticity that helps younger brains adapt may also create conditions that support the development of seizure-producing networks,” Reddy said in a press release. While the younger mice developed epilepsy later, once the process took hold, their seizure burden became substantially greater.
Older mice, by contrast, were more likely to show seizure activity earlier after the injury, but they had a lower overall incidence and burden of post-traumatic epilepsy.
In other words, the younger brain may respond better to damage due to the brain’s ability to alter its connections and organisation in response to experience or injury. But it may also create abnormal connections that contribute to seizure-producing networks.
Memory is a different story
The older mice actually showed faster improvement in some measures of motor function. Yet ageing came with its own costs.
Older animals showed stronger signs of neuroinflammation and abnormal circuit remodelling, and had bigger problems with long-term memory retention.
“Aging changed the path of recovery rather than simply making recovery more difficult,” Reddy said. “Older brains appeared less susceptible to chronic seizure activity, but they remained vulnerable in other ways, particularly when it came to memory and cognitive function.”
The findings suggest that the long-term consequences of brain injury may be shaped not simply by how much physical damage occurs, but by how the brain responds to that damage over time.
That could help explain why two people with apparently similar injuries can experience very different long-term outcomes.
The research also offers clues about why age might matter when studying the consequences of traumatic brain injury. In younger brains, the concern may be the gradual development of abnormal, seizure-producing networks. In older brains, inflammation, circuit changes and memory decline may be more prominent features.
“A younger brain may require interventions aimed at preventing the gradual development of seizure-producing networks,” Reddy said, “while older brains may benefit from approaches that address memory loss, inflammation and cognitive decline following injury.”
