Blows to the head—even mild ones—can interrupt the production of neurons in the brain responsible for memory. Researchers note that this finding raises questions about the long-term effects of repeated injuries and the academic performance of student-athletes.

After following dozens of athletes involved in high-contact sports such as rugby and football, researchers from McMaster University suggest that concussions and repetitive impact can interrupt neurogenesis—or the creation of new neurons—in the hippocampus, a vulnerable region of the brain critical to memory.

“Not only are newborn neurons critical for memory, but they are also involved in mood and anxiety,” explains Melissa McCradden, a neuroscience postdoctoral fellow at McMaster University, in a study presented recently at the Society for Neuroscience’s annual conference, Neuroscience 2017.

“We believe these results may help explain why so many athletes experience difficulties with mood and anxiety in addition to memory problems,” she adds, in a media release from McMaster University.

In the study, the release explains, researchers administered memory tests and assessed different types of athletes in two blocks over the course of 2 years. In the first block, they compared athletes who had suffered a concussion, uninjured athletes who played the same sport, same-sport athletes with musculoskeletal injuries, and healthy athletes who acted as a control group.

Concussed athletes performed worse on the memory assessment called a mnemonic similarity test (MST), which evaluates a person’s ability to distinguish between images that are new, previously presented, or very similar to images previously presented.

In the second study, rugby players were given the MST before the season started, halfway through the season, and 1 month after their last game. Scores for injured and uninjured athletes alike dropped midseason, compared to preseason scores, but recovered by the postseason assessment.

Both concussed and non-concussed players showed a significant improvement in their performance on the test after a reprieve from their sport, the release continues.

For the concussed athletes, this occurred after being medically cleared to return to full practice and competition. For the rugby players, they improved after approximately a month away from the sport.

If neurogenesis is negatively affected by concussion, researchers say, exercise could be an important tool in the recovery process, since it is known to promote the production of neurons. A growing body of new research suggests that gentle exercise, which is introduced before a concussed patient is fully symptom free, is beneficial.

“The important message here is that the brain does recover from injury after a period of reprieve,” McCradden states in the release. “There is a tremendous potential for the brain to heal itself.”

[Source(s): McMaster University, EurekAlert]