Original Academic Latitude Academic Latitude 2024-06-27 08:02 Shanghai
Many studies have shown that positive emotions and a good psychological state can help delay the cognitive decline of the brain, reduce the risk of brain diseases such as Alzheimer's disease in old age, and even prolong life. But how does a healthy mental state protect the brain on a physiological level?
Recently, researchers at Columbia University's Irving Medical Center found an important clue. According to their paper published in the Proceedings of the National Academy of Sciences (PNAS), the less psychological stress a person experiences in a lifetime, the stronger the metabolic function of mitochondria in brain cells, and mitochondria may be the key to protecting the brain.
Mitochondria are often referred to as the "batteries" of the cell because they are the site of the production of the energy molecule ATP, which produces the chemical energy required for cellular life through the process of oxidative phosphorylation (OXPHOS). In addition, mitochondria metabolize cholesterol and synthesize hormones and neurotransmitters.
Because of this, mitochondria can lead to a wide variety of diseases if they become dysfunctional. There are more than 50 diseases known to be associated with mitochondrial dysfunction, including rare genetic diseases and common aging-related diseases, as mitochondria continue to age and be impaired with age.
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In this study, the scientists focused on the mitochondrial phenotype in the brains of older adults and correlated it with their psychological states in their life experiences.
Based on data collected from two long-term surveys, the researchers obtained psychosocial information about 450 older adults over the first two decades of their lives, including their self-reported chronic stress levels and emotional states, and then constructed a scoring method that converted positive or negative psychosocial factors into specific scores. At the same time, thanks to the brains donated by these elderly volunteers who participated in the survey, the researchers also analyzed their brains through proteomics, single-core RNA sequencing and other methods, including the gene network in the cells, mitochondrial oxidative phosphorylation complexes and other key protein levels necessary for mitochondrial metabolic function.
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As a result, the researchers found interesting associations: the higher a person's psychosocial score—the more positive the mood and the greater the sense of well-being—the higher the content of oxidative phosphorylation complexes in the dorsolateral prefrontal cortex of the brain, mitochondria; Conversely, people with higher negative emotions have lower levels of proteins necessary for mitochondrial metabolism. "The 18%~25% difference in the abundance of oxidative phosphorylation complex I can be explained by a combination of positive and negative psychosocial factors." The paper states:
Given that the prefrontal cortex is a key brain region in the brain responsible for higher cognitive tasks such as decision-making and behavior, this link suggests that chronic psychological stress and negative experiences may adversely affect the brain by impairing mitochondrial energy metabolism in the prefrontal cortex, thereby changing people's social behavior and stress response.
The study authors note that these results demonstrate that the mental state of older adults is related to the mitochondrial biology of their brains, and that this is the first evidence that subjective psychosocial experiences are related to brain biology.
The study further analysed different types of brain cells and found that the association between mitochondria and psychosocial factors was primarily driven not by neurons in the brain but by glial cells at single-cell resolution.
These findings suggest that targeting the mitochondrial function of specific cells may help reverse the damage of negative experiences and negative emotions to the brain, allowing the brain to gain more "positive energy".
Resources:
[1] Caroline Trumpff et al, Psychosocial experiences are associated with human brain mitochondrial biology, Proceedings of the National Academy of Sciences (2024). DOI: 10.1073/pnas.2317673121
[2] Brain health is rooted in state of mind, finds study. Retrieved June 25, 2024 from https://www.cuimc.columbia.edu/news/brain-health-rooted-state-mind-finds-study