Axons In Brains Of Female Mammals May Be More Vulnerable To Damage, Penn Medicine Research Finds

Our interest in concussion started back in September 2023, when we began to investigate differences in recovery between men and women. It has been so inspiring to see new research and news articles released daily highlighting the importance of this topic. It has provided ongoing motivation to the team to provide a solution to this problem. Women should not be treated as small men. 

From early research stages, we discovered complexities in the problem – why is it that there are differences in concussion outcomes between men and women?

“Clinicians have observed for a long time that females suffer from concussion at higher rates than males in the same sports, and that they take longer to recover cognitive function, but couldn’t explain the underlying mechanisms of this phenomenon,” said Douglas Smith, MD, a professor of Neurosurgery and director of Penn’s Center for Brain Injury and Repair. 

A preclinical study led by the Perelman School of Medicine at the University of Pennsylvania finds that structural differences in male and female brains could explain why females are more prone to concussions and experience longer recovery from the injury than their male counterparts. 

Axons are lines that connect brain cells, allowing communication across the brain, and are vulnerable to damage from concussion. Communication between axons is powered by sodium channels that act as the brain’s ‘electric grid’. When axons are damaged, sodium channels are also impaired and there is a loss of signalling in the brain, which causes cognitive impairment.  

This study finds that females have a higher population of smaller axons compared to men, which are more vulnerable to injury, as seen in the image below. It also finds that females have greater loss of sodium channels after a concussion. These differences in brain structure could explain how brain injuries affect males and females differently.