GUEST POST: Learning to navigate a city, but reducing memory symptoms

GUEST POST: Learning to navigate a city, but reducing memory symptoms

Could building up navigation skills help reduce memory symptoms in MS patients? These researchers think it might just.

July 17, 2021

Multiple Sclerosis. Traumatic Brain Injury. Early Life Trauma. Type 2 Diabetes. Dementia. While this might seem like healthcare terminology word-vomit, these are all connected by an important principle of brain health. Read on to learn what that principle is.

On occasion, Mother Nature can be a bit lazy and upcycle existing brain structures to use them for new functions. This is certainly true for the Hippocampus, the brain structure critically involved in long term memory. At the risk of not offending Mother Nature though, perhaps a more accurate description is that the memory capabilities of the hippocampus evolved from the ability to do other things. For the study we will be talking about today, those other things are what we trust Google Maps to do: get us from point A to point B. While the Hippocampus is probably more well known for its role in memory, the 2014 Nobel Prize in Physiology was awarded to neuroscientists studying its role in spatial cognition and navigation. This opens up an interesting question though: Are there links between navigation ability and memory skills?

Dr. Green and Dr. Gilboa at the University of Toronto are currently addressing that in a Branch Out-funded study and the early results suggest yes. To be more precise, they are testing the hypothesis that building up navigation skills can reduce memory symptoms in Multiple Sclerosis (MS) patients. As an autoimmune disorder, the primary feature of MS is a malfunction in the immune system that causes it to attack our own body. In the case of MS, this attack is on the gial cells that support information transmission in the brain. While the motor and depression symptoms of MS are well known, studies often also find evidence of learning and memory difficulties in people with MS2. Since the Hippocampus is sensitive to high levels of inflammation, its perhaps not surprising that this brain structure is often smaller in people with MS, which in turn results in the memory problems observed in MS cases3. This sets the stage for Dr. Green and Dr. Gilboa’s study, where they had people with MS do a 4-month long training program to develop navigation abilities in foreign cities using Google Maps. Follow this link to view their recruitment video and see what the program entailed. While preliminary results need to be taken with a grain of salt, it is optimistic that some memory scores improved substantially in people with MS after this program. Additionally, this program impacted people with MS on a more personal level, returning the feeling of competency and the joy of exploration that the disorder had taken from them. Combine this with the fact that the program can be delivered remotely; this could be a really promising COVID-proof intervention to treat an often overlooked component of MS all across Canada. No big deal, but this project did win the 2020 Focus on Accessibility Award in recognition of that fact.

Ready for the M. Night Shyamalan-grade twist? Remember that list of healthcare jargon from the top? Turns out, each of those conditions is associated with chronic inflammation and Hippocampal damage or memory impairments4-6. While there are disease-specific factors to consider, like the damaged glial cells in MS, or the toxic effects of stress hormones seen in early life trauma cases, these common features across the various conditions open the door to common treatments for each of them. That means this navigation program could improve memory symptoms not only in MS, but several other disorders as well. In fact, Dr. Green and Dr. Gilboa’s study was inspired by research on how aging impacts the Hippocampus, and they have preliminary evidence for similar memory improvements in not only older adults, but brain injury patients as well! While the modern medical system often focuses on categorizing disorders as distinct things, this can often obscure the common transdiagnostic factors, like inflammation, that can have an important role in many different disorders. In the same way that our Hippocampus is responsible for both navigation and long-term memory, identifying these transdiagnostic factors allow us to develop treatments for one disorder and apply them to other clinical populations based on common disease processes. Of course, there is still a need to consider disorder-specific factors when developing treatments-the challenges faced by people with MS can look very different from the challenges faced by early stage dementia patients. Considering this navigation program has the potential to benefit not only people with MS, but also older adults and brain injury patients, Branch Out is funding an additional student in the lab, Thomas Worthington, to better understand the unique challenges faced by each population. Overall, this line of research is a great example of how neuroscientists can take inspiration from Nature and upcycle treatments based on transdiagnostic factors to ultimately boost their impact for society.

This study was funded by the Branch Out Neurological Foundation, in partnership with the Ralph M. Barford Foundation.

References

1. Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Good, C. D., Ashburner, J., Frackowiak, R. S., & Frith, C. D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences, 97(8), 4398-4403.

2. Prakash, R. S., Snook, E. M., Lewis, J. M., Motl, R. W., & Kramer, A. F. (2008). Cognitive impairments in relapsing-remitting multiple sclerosis: a meta-analysis. Multiple Sclerosis Journal, 14(9), 1250-1261.

3. Rocca, M. A., Barkhof, F., De Luca, J., Frisén, J., Geurts, J. J., Hulst, H. E., … & Enzinger, C. (2018). The hippocampus in multiple sclerosis. The Lancet Neurology, 17(10), 918-926.

4. Tursich, M., Neufeld, R. W. J., Frewen, P. A., Harricharan, S., Kibler, J. L., Rhind, S. G., & Lanius, R. A. (2014). Association of trauma exposure with proinflammatory activity: a transdiagnostic meta-analysis. Translational psychiatry, 4(7), e413-e413.

5. Lai, K. S. P., Liu, C. S., Rau, A., Lanctôt, K. L., Köhler, C. A., Pakosh, M., … & Herrmann, N. (2017). Peripheral inflammatory markers in Alzheimer’s disease: a systematic review and meta-analysis of 175 studies. Journal of Neurology, Neurosurgery & Psychiatry, 88(10), 876-882.

6. Gold, S. M., Dziobek, I., Sweat, V., Tirsi, A., Rogers, K., Bruehl, H., … & Convit, A. (2007). Hippocampal damage and memory impairments as possible early brain complications of type 2 diabetes. Diabetologia, 50(4), 711-719.

7. Lövdén, M., Schaefer, S., Noack, H., Bodammer, N. C., Kühn, S., Heinze, H. J., … & Lindenberger, U. (2012). Spatial navigation training protects the hippocampus against age-related changes during early and late adulthood. Neurobiology of aging, 33(3), 620-e9.