The brain is the most complex structure known to humankind. There are 7.8 billion people in the world and there are over 100 billion neurons in our brain. Want to know a fact that will make any introvert the life of a cocktail party? There are more connections between neurons in the brain than there are stars in the Milky Way! Even though there are billions of neurons, we need to protect these little guys; furthermore, when neurons lose function or die off sooner than programmed, profound effects manifest. For example, Parkinson’s Disease is a loss of dopaminergic neurons in the substantia nigra, and Dementia is damage to neurons in the hippocampus. Reasons for the mishaps are due to genetic and environmental factors. A big player in today’s research is stress.
Some rocks become diamonds under extreme stress; however, our brains can have abstruse effects. What is stress? Stress can be chemical, physical, and emotional. There is positive stress, where our sympathetic nervous system is stimulated and we run from a dangerous animal. However, there is also negative stress. An interesting study in The Journal of Neuroscience found evidence to support acute stress remodels the brain. According to researchers, when a person is presented with a stressor, noradrenaline is released and causes a reduction in GluA1 protein production. When this protein is halted, astrocytes are retracted. Astrocytes are glial cells in the brain responsible for support, metabolic functions, and decreasing inflammation. When astrocytes are retracted, there is no re-uptake of neurotransmitters and there is disruption in neuron communication. When our brains are put under a lot of stress, it can affect our memory, promote inflammation, and increase the risk for neurological disorders like dementias.
According to The Frontiers of Psychology Journal, researchers found an easy way to reduce levels of stress. Participants were required to have a nature experience 3 times a week for more than 10 minutes. Researchers swabbed mouths for salivary cortisol and salivary alpha-amylase levels before and after each nature experience. After 8 weeks, data showed cortisol levels dropped by a significant 21% per hour and alpha-amylase dropped 28% per hour. Research showed the biggest drop in levels after 20 and 30 minutes of outdoor activity. When time spent outdoors was longer than 30 minutes, data continued to show a decrease; however, levels of stress hormones dropped at a much slower rate. In conclusion, when you start feeling tension, enjoy the outdoors for 20-30 minutes and protect your brain from stress!
Bender, C., Davison, C., Farooq, M., Huang, Y., Ishikawa, Y., Liu, S., Maroteaux, M. (2020). Emotional stress induces structural plasticity in bergman glial cells via an AC5-CPEB3-GluA1 pathway. Journal of Neuroscience, 40(17), 3374-3384. Retrieved from: https://www.jneurosci.org/content/40/17/3374
Hunter, M., Chen, S., Gillespie, B. (2019). Urban nature experiences reduce stress in the context of daily life based on salivary biomarkers. Journal of Frontiers in Psychology, 10. Retrieved From: https://www.frontiersin.org/articles/10.3389/fpsyg.2019.00722/full#h1
Written by Hunter Hill, CNIM