Going for a run 'helps preserve memory'

Running helps preserve your memory, suggests new research.

Scientists found any exercise, but running in particular, protects against the negative effects of stress on the hippocampus - the part of the brain responsible for learning and memory.

Associate professor Jeff Edwards, of Brigham Young University in the US, said: "Exercise is a simple and cost-effective way to eliminate the negative impacts on memory of chronic stress,

"The ideal situation for improving learning and memory would be to experience no stress and to exercise

"Of course, we can't always control stress in our lives, but we can control how much we exercise.

"It's empowering to know that we can combat the negative impacts of stress on our brains just by getting out and running."

Stress relief

Prof Edwards explained inside the hippocampus, memory formation and recall occur optimally when the synapses or connections between neurons are strengthened over time.

That process of synaptic strengthening is called long-term potentiation (LTP).

Yet chronic or prolonged stress weakens the synapses, which decreases LTP and ultimately impacts memory.

So he and colleagues divided mice into four groups - sedentary no stress, exercise no stress, exercise with stress, and sedentary with stress.

The exercise groups used running wheels over a four-week period averaging 5 km ran per day.

Half of each exercise and sedentary group was then exposed to stress-inducing situations, such as walking on an elevated platform or swimming in cold water.

One hour after stress induction researchers carried out electrophysiology experiments on the animals' brains to measure the LTP.

Maze runners

The study found when exercise co-occurs with stress, LTP levels are not decreased, but remain normal.

Stressed mice who had exercised had significantly greater LTP than the stressed mice who did not run.

The stressed mice who exercised performed just as well as non-stressed mice who exercised on a maze-running experiment testing their memory.

Additionally, Prof Edwards found exercising mice made significantly fewer memory errors in the maze than the sedentary mice.

The findings reveal exercise is a viable method to protect learning and memory mechanisms from the negative cognitive impacts of chronic stress on the brain.

The study was published in the journal of Neurobiology of Learning and Memory.