Friday, April 23, 2021

Tread new paths to cognitive resilience.


Imagine a woodland, blanketed with knee high snow. On foot, you need to cross. Those first few crossings are tough, lifting your feet high, then crushing the snow underneath. With repetition, you’ve built a path and your crossing is made faster and easier. One day an interesting birdsong catches your attention and you stray from your worn path, starting a new one. 

For several days, you follow the new path hoping to catch a glimpse of the elusive bird. Now you have two worn paths. Every so often, exploring the reaches of the woodlands, you create and then retrace new paths. A large tree breaks under the weight of the snow, completely blocking your first, main path. Because you branched out, explored new areas, you have options.

Applied to the brain in a general way, this scenario represents the real-world value of neuroplasticity. Our brain function relies on fast and accurate communication of sensory inputs and responses, travelling through chains of brain cells (neurons) where chemical neurotransmitters serve as the language of that communication. Well-used neuron chains are in effect the snow-packed paths in the woodland.

Neuroplasticity describes how experience and environment trigger the brain to form new connections and pathways. Should a brain injury occur - stroke, trauma, or other - neuroplasticity allows for workarounds that can compensate for impaired function.  This capacity is crucial to rehabilitative therapies. 1 

But neuroplasticity is also key to managing risk and slowing progression of neurocognitive disorders, including those resulting in Dementia.  New and novel experiences, no matter the type, lay down new pathways connecting different areas of the brain. These pathways allow for learning a new task, or committing to memory the sights, sounds, and sensations of a new destination. They open up a network of routes for neuro-communication that can be used for a range of function much broader than the original task or experience would suggest.

While repetition builds stronger pathways, recent investigation suggests that prolonged experiences such as physical exercise or stress can change the language of communication between neurons, substituting one neurotransmitter for another. 

A study of mice running in a wheel demonstrated both the switch-up in neurotransmitter and an overall improvement in coordination and motor learning. 2 Not only did they run faster, the mice had an improved ability to walk a tightrope and balance on a rotating rod. 

This process, the neurotransmitter switch, is of interest to researchers examining mechanisms behind stress induced disease. It will also be important as we learn how targeted exercise might be used as treatment for other diseases. 

Another related area of study with great potential is neurogenesis- the creation of new neurons. Neurogenesis is regulated by neurotransmitters – think of the study of mice in the running wheel. While neurogenesis is slowed by stress and aging, rates can be accelerated by physical exercise and brain exercise, for example learning new concepts or skills. Of course, many other molecular mechanisms also affect the process of neurogenesis. 3  

Neuroplasticity is as complex as it is crucial to our cognitive health. A technical summary would be that curiosity, physical activity, and novel experiences enhance neuroplasticity through mechanisms such as the neurotransmitter switch and neurogenesis. A practical summary though - while the main path may be easy, it would serve us well to tread more paths. Even better, use different tools like skis, snowshoes, or crampons, and skills like using a bird guide, binoculars, and journaling your experiences. 

1 Ackerman, Courtney E., MA. What is Neuroplasticity – A Psychologist Explains. Accessed 4/15/2020 from https://positivepsychology.com/neuroplasticity/

2 University of California Television. 30 June 2017.  “Neuroplasticity: Our Adaptable Brain with Nick Spitzer”. [Show ID: 32521] Accessed 15 April 2021 from https://www.youtube.com/watch?v=DXA_iTG3XSM

3 Ming, Guo-Li, and Hongjun Song. “Adult neurogenesis in the mammalian brain: significant answers and significant questions.” Neuron vol. 70,4 (2011): 687-702. doi:10.1016/j.neuron.2011.05.001 Accessed 15 April, 2021 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3106107/

Contributor: Karen R. Ogden, team member, Dementia Society of America.
The opinions expressed by contributing authors are not necessarily the opinions of the Dementia Society, Inc. We do not endorse nor guarantee products, comments, suggestions, links, or other forms of content contained within blog posts that have been provided to us with permission, or otherwise. Dementia Society does not provide medical advice. Please consult your doctor. www.DementiaSociety.org