Why exercise helps memory and learning

May, 2012

A mouse study suggests exercise increases neurogenesis through muscles’ release of an enzyme that affects energy and metabolism — an enzyme whose production lessens with age.

A number of studies, principally involving rodents, have established that physical exercise stimulates the creation of new brain cells in the hippocampus. A recent study attempted to uncover more about the mechanism.

Using two drugs that work directly on muscles, producing the physical effects of exercise, the researchers compared the effects on the brain. One drug (Aicar) improves the fitness of even sedentary animals. The other drug increases the effects of exercise on animals that exercise, but has little effect on sedentary animals.

After a week of receiving one of the drugs, sedentary mice performed better on tests of memory and learning, and showed more new brain cells. These effects were significantly greater for those taking Aicar.

Because the drugs have very little ability to cross into the brain, this demonstrates that the neurogenesis results from exercise-type reactions in the muscles, not to brain responses to the drugs. Indeed, previous research has found that direct infusion of Aicar into the brain impaired learning and memory.

Aicar increases the muscles’ output of AMPK, an enzyme that affects cellular energy and metabolism. It’s speculated that some of this enzyme may enter the bloodstream and travel to the brain. Interestingly, as with neurogenesis, AMPK activity in muscles appears to decline with age. It may be that AMPK production could serve as a biomarker for neurogenesis, as well as being a target for improving neurogenesis.

These findings add weight to evidence for the value of aerobic exercise over other types of exercise (given that the mice exercise by running). However, I see that human research has found that resistance training (which is difficult to study in mice!) also increases AMPK activity.

Do note — if you are hopeful that drugs will relieve you of the need to exercise — that the benefits were not only smaller than those achieved from exercise, but also didn’t last. In those mice taking Aicar for a second week, their brains not only stopped deriving any benefit, but actually deteriorated.


Related News

Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.

Unplanned hospitalizations accelerate cognitive decline in older adults

Data from the Rush Memory and Aging Project has found that emergency and urgent hospitalizations are associated with an increased rate of cognitive decline in older adults.

A Finnish study involving 338 older adults (average age 66) has found that greater muscle strength is associated with better cognitive function.

Data from over 11,500 participants in the Atherosclerosis Risk in Communities (ARIC) cohort has found evidence that orthostatic hypotension in middle age may increase the risk of cognitive impairment and dementia 20 years later.

A review of 39 studies investigating the effect of exercise on cognition in older adults (50+) confirms that physical exercise does indeed improve cognitive function in the over 50s, regardless of their cognitive status.

A Canadian study involving 40 older adults (59-81), none of whom were aware of any major memory problems, has found that those scoring below 26 on the Montreal Cognitive Assessment (MoCA) dementia screening test also showed shrinking of the anterolateral

A study involving 35 adults with

In Australia, it has beens estimated that 9% of people aged over 65, and 30% of those aged over 85 have dementia. However, these estimates are largely based on older data from other countries, or small local samples.

In the past few months, several studies have come out showing the value of three different tests of people's sense of smell for improving the accuracy of

A study comparing the language abilities of 22 healthy young individuals, 24 healthy older individuals and 22 people with


Subscribe to Latest newsSubscribe to Latest newsSubscribe to Latest health news