Motivation is important for goal-directed behavior, performance, and well-being.
To research motivation, scientists engaged 27 men (ages 20-30) in a hand-grip challenge, where they got paid increasing sums of money for expending greater effort at the task. Participants did not differ in key personality traits, levels of physical activity, or body mass index.
Researchers used a brain imaging technique called proton magnetic resonance spectroscopy (1H-MRS) to measure the levels of glutamate, GABA, and glutamine in the brain. About 80% of the signaling in the brain is conducted by glutamate, which activates brain cells, and GABA, which calms brain cells. Glutamine is converted into glutamate by brain cells. The research revealed that a higher glutamine to glutamate ratio in the nucleus accumbens, an area in the brain’s motivation and reward system, predicts better overall performance, stamina, and reduced effort perception.
While scientists have more to learn about the glutamine to glutamate ratio, they already know that the balance between glutamate and GABA is important to physical and mental health. Glutamate is important to learning and memory, but levels that are too high have a role in Alzheimer’s disease and ALS. Depression has been linked to low levels of both glutamate and GABA.
Exercise increases and balances both glutamate and GABA. It also helps the brain metabolize glutamate more effectively, reducing its buildup. Another strategy for maintaining the balance between glutamate and GABA is to avoid Monosodium glutamate (MSG) and the artificial sweetener aspartame. Calming practices such as yoga, meditation, and deep breathing increase GABA levels. And the motivation study acknowledged that glutamine supplements have been reported in other research to reduce perceived exertion and fatigue during demanding tasks, and to increase glutamine in the brain.
Takeaway: Maintaining brain balance is enhanced by activating the body with exercise and calming it with meditation and yoga.
Strasser, A., Luksys, G., Xin, L. et al. Glutamine-to-glutamate ratio in the nucleus accumbens predicts effort-based motivated performance in humans, Neuropsychopharmacol, July 20, 2020, https://doi.org/10.1038/s41386-020-0760-6, https://www.nature.com/articles/s41386-020-0760-6#citeas.
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