Overview: Higher nucleus accumbens glutathione levels led to better and more stable performance on motivation-based tasks. Our findings suggest that improving the antioxidant function of the sciatic bone, which can be obtained through diet or supplementation, may be a viable approach to increasing motivation.
sauce: EPFLMore
In life, motivation can be the difference between success and failure, goal-setting and aimlessness, happiness and unhappiness. This is the problem that prompted the study of
A small part of that work looks at metabolic issues. “Do differences in metabolites in the brain affect our ability to motivate?” says Professor Carmen Sandi of EPFL’s Faculty of Life Sciences. asks. “If so, could nutritional interventions that could affect metabolite levels be an effective means of improving motivated performance?”
Sandi’s group, along with colleagues from the Nestlé Institute for Health Sciences, have published the first study to shed light on that question. The researchers turned to a region deep in the brain called the nucleus accumbens, which is known to play a major role in regulating functions such as reward, reinforcement, aversion, and especially motivation.
Brain metabolism and oxidative stress
The idea behind this research was that the brain itself, like all tissues in our body, is constantly exposed to oxidative stress as a result of its metabolism.
What is oxidative stress? As cells ‘eat’ various molecules for fuel, they produce many toxic waste products in the form of highly reactive molecules collectively known as ‘oxidizing species’. Of course, cells have many mechanisms to remove oxidative species and restore the cell’s chemical balance. However, that battle is ongoing, and sometimes that balance is disturbed, and that disturbance is what is called “oxidative stress.”
glutathione connection
The brain is then often subjected to excessive oxidative stress from its neurometabolic processes. The question for researchers was whether antioxidant levels in the nucleus accumbens could influence motivation. To answer the question, scientists looked at a protein called glutathione (GSH), the brain’s most important antioxidant, and its relationship to motivation.
“We evaluated the relationship between metabolites in the nucleus accumbens, a key region of the brain, and motivational performance,” says Sandi. “We then turned to animals to understand the mechanisms and explore causal relationships between the discovered metabolites and performance, and also demonstrated that nutritional interventions modify behavior through this pathway.”
Tracking of GSH in the nucleus accumbens
First, they used a technique called “proton magnetic resonance spectroscopy.” This allows the biochemistry of specific regions of the brain to be assessed and quantified in a non-invasive manner.
The researchers applied this technique to the nucleus accumbens of both humans and rats to measure levels of GSH. Those levels were then compared to how well, or how poorly, human and animal subjects performed on standardized effort-related tasks that measure motivation.
What they found was that higher GSH levels in the nucleus accumbens correlated with better and more stable performance on motivational tasks.
GSH level and motivation
However, correlation does not imply causation, so the researchers moved to microinjecting rats with a GSH blocker to downregulate antioxidant synthesis and levels. The rat was de-motivated, as seen in his performance decline on the effort-based reward incentive test.
On the contrary, when the researchers gave rats a nutritional intervention with the GSH precursor N-acetylcysteine (which increases GSH levels in the nucleus accumbens), they improved their performance. As the authors write, this effect was “potentially mediated by a cell type-specific shift of glutamatergic input to nucleus accumbens medium spiny neurons”.
Can nutrition and supplements help motivate you?
“Our study provides new insight into how brain metabolism is linked to behavior and targets key oxidative processes as an ideal intervention to promote endurance in effort.” The results of this study suggest that “improving the antioxidant function of the sciatic bone may be a viable approach to increasing motivation.” suggesting.”
“N-acetylcysteine, the dietary supplement we gave in our study, can also be synthesized in the body from its precursor cysteine.” ” is included. Other sources of low content are eggs, whole grain foods such as bread and cereals, and some vegetables such as broccoli, onions, and legumes.
“Of course, there are ways to increase GSH levels in the body other than N-acetylcysteine, but we know very little about how they relate to levels in the brain, especially in the nucleus accumbens. Our study represents proof-of-principle that dietary N-acetylcysteine can increase brain GSH levels and promote strenuous behavior.”
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About this motivation and neuroscience research news
author: press office
sauce: EPFLMore
contact: Press Office – EPFL
image: image is public domain
Original research: open access.
“Glutathione in the nucleus accumbens modulates motivation for reward-seeking efforts”, Ioannis Zalachoras et al. e-life
Overview
Glutathione in the nucleus accumbens modulates motivation for reward-seeking efforts
Emerging evidence implicates mitochondrial function and nucleus accumbens metabolism in motivational performance.
However, the brain is vulnerable to excessive oxidative damage resulting from neurometabolic processes, and it is unclear whether antioxidant levels in the nucleus accumbens contribute to motivated performance.
Here, we identify a key role in motivation for glutathione (GSH), the most important endogenous antioxidant in the brain.
Using proton magnetic resonance spectroscopy (1H-MRS) in both the clinical and preclinical populations at ultra-high fields strongly demonstrated that higher sciatic GSH levels lead to improved performance over time on effort-related tasks, with particularly stable performance. proved to be predictable.
A causal relationship was established in preclinical in vivo experiments, first showing that downregulation of GSH levels by microinjection of the GSH synthesis inhibitor buthionine sulfoximine into the nucleus accumbens impairs effort-based reward incentive performance. was shown.
Furthermore, systemic treatment with the GSH precursor N-acetyl-cysteine (NAC) increased sciatic GSH levels and led to improved performance. Our data show that there is a close association between her GSH levels in the cruciate bone and an individual’s ability to perform reward-seeking efforts over time.
They also suggest that improving the antioxidant function of the sciatic bone may be a viable approach to increasing motivation.
