Although the enhancing effect of exercise on neurogenesis has been extensively studied, the molecular mechanisms behind this response are not well understood by researchers. Recently, a research report published in the international journal Cell Metabolism entitled "Selenium mediates exercise-induced adult neurogenesis and reverses learning deficits induced by hippocampal injury and aging", Scientists from the University of Queensland and other institutions have found that a mineral present in many foods, selenium, can reverse the impact of stroke on the body's cognitive ability and enhance the learning and memory ability of aging brains.
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In the article, the researchers analyzed the effects of exercise on aging brains and found that the level of a protein that is critical to transporting selenium in the blood may be elevated through physical exercise. Over the past 20 years, scientists have known that exercise may produce new neurons in the brain, but they don't know the molecular mechanisms. To that end, the scientists investigated whether dietary selenium supplementation could replicate the effects of exercise, and they found that selenium supplementation may increase the production of neurons in the body of old mice and improve their cognitive function.
The level of production of newborn neurons decreases rapidly in the body of older mice, as in humans. When selenium supplementation was given to mice, the level of neuronal production in their bodies increased, reversing the cognitive deficits observed in senescent mice.
Selenium is an essential trace mineral absorbed from soil and water, which is found in foods such as grains, meats and nuts, with the highest content in Brazil nuts. The scientists also analyzed whether selenium would have an impact on the decline in the body's cognitive function after a stroke, which may affect the body's ability to remember and learn. Researcher Dr. Walker said that young mice tend to perform better in learning and memory tasks, but after stroke, they can no longer perform these tasks, and when given selenium supplements to mice, mice affected by learning and memory deficits caused by stroke will return to normal.
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The findings may help scientists develop novel therapeutic strategies to enhance brain cognitive function in people who are incapable of exercising due to poor health or old age; however, selenium supplementation may not be considered a complete substitute for exercise, and excessive intake of selenium supplementation may be harmful to the health of the body; a person who receives a balanced diet of fruits, nuts, vegetables and meats tends to have good selenium levels; but selenium supplementation may be beneficial in the elderly, especially in patients with neurological disorders.
Taken together, the results of this paper provide a particular molecular mechanism that may correlate systemic environmental changes induced by exercise with the activation of resting hippocampal neural precursor cells and their subsequent recruitment into neural source trajectories.
Original source:
Odette Leiter，Zhan Zhuo，Ruslan Rust,et al. Selenium mediates exercise-induced adult neurogenesis and reverses learning deficits induced by hippocampal injury and aging, Cell Metabolism (2022). DOI:10.1016/j.cmet.2022.01.005