An international team from QBI and the Dresden University of Technology has discovered a new way in which exercise boosts our brain.

Dr Tara Walker said while researchers have long known that exercise improves brain function, what wasn’t clear was the underlying mechanism.

“When we exercise, stem cells in the hippocampus, a region of the brain that plays an important role in learning and memory, divide and turn into new neurons, which leads to improvements in memory,” she said.

“But how do the stem cells know to start dividing and form neurons after exercise, in other words, how does running change our brain?”

“When we exercise, it’s likely that our blood composition also changes, so we decided to investigate blood to see what post-exercise changes might influence the neural stem cells and cause them to form new neurons.”

To test this theory, the researchers screened the blood of mice who had been running and compared it to control mice who didn’t have running wheels.

Dr Odette Leiter said the team found a lot of the changes that occurred in the blood following exercise were related to platelets, small cells in our blood.

“We found that platelets caused neural stem cells to multiply and develop into neurons, as opposed to other cell types that they also have the potential to form,” she said.

“Platelets are mostly known for their role in wound healing - they cause blood to clot and skin cells to adhere together – but we found the response activated in platelets after running was different to their wound healing response.

“It’s exciting because platelets are a lot more complex than originally thought, with the ability to release different molecules depending on the stimulus that has triggered them.”

Dr Walker said the discovery added to our fundamental knowledge of how changes to the body affect the brain, and opened up intriguing new questions and research possibilities, especially in ageing.

“The growth of new neurons decreases significantly with age, which leads to cognitive decline in specific types of learning and memory,” she said.

“Our next step is to investigate whether we can harness the positive effect of platelets to boost neuron development and improve learning and memory in both mice and humans.

The research was published in Stem Cell Reports with much of the work taking place in Dresden.

Dr Walker, who has previously worked at QBI, has returned with Dr Leiter to progress this exciting research through collaborations and facilities available at the institute.