Brain Health

Like most of you, I try to be resource conscious whenever possible; sometimes I do a good job and other times not so much. But hey, I try to focus not so much on perfection, but rather the pursuit of perfection.

During my previous professional life as a neuroscience researcher, I gained steady exposure to concepts and systems relating to health and wellness. It’s true that there’s a difference between knowing and understanding, and having made such a transition into tech, it’s clear that there are things the other fields are simply not aware of. Take code repository platforms, for example - academics just tend not to have accounts on GitHub, GitLab, or Codeberg. Bash scripting, containers, and languages other than python or R? For the most part, forget about it. The same can be said of the tech community and their awareness of some biological concepts that affect their daily lives.

Considering this, I feel I have the opportunity to share some of my learnings and not only explain why the brain is a very valuable resource, but express how I feel that it is being mistreated.

So today, I speak for the brain.

Try to focus not so much on perfection, but the pursuit of perfection.

Contents

• Why sleep?
• Biological underpinnings
• Relationship to industry
• References

Why sleep?

Silly question, right? Let me tell you something though: similar to today’s ubiquitous access to food and water, I’m confident that we’re losing touch with how much sleep we really need, and how much of a finite resource it really is. This trifecta is non-negotiable, full stop. Days without water, weeks without food, something something without sleep. Aha - there’s the devil in the details we were looking for. While issues related to dehydration and starvation and pretty well mapped out, comparative issues to sleep deprivation, sleep fragmentation, inconsistent sleep schedules, and so on, are certainly not as “tableside conversation” as the other two.

A lot happens when we sleep, for example memory allocation (Brodt et al., 2023), but for now I’ll focus moreso on brain waste clearance.

Biological underpinnings

Fun fact: every night when we sleep, the brain washes itself of its naturally-occurring metabolic byproducts (Hablitz et al., 2020; Kroesbergen et al., 2024).

You see, the brain (cerebral) and spinal cord are bathed in a fluid aptly named the cerebrospinal fluid. It travels alongside the arteries, into the brain tissue, and eventually out of that space and processed by the rest of the body. These phenomena are collectively known as the Glymphatic System and has applications in aging, Alzheimer’s disease, traumatic brain injury, and more (Jessen et al., 2015).

This is by no means a stagnant system. Indeed, there are many things that either help or hurt it. Here’s a non-exhaustive list:

To keep things managably short, here’s a video I recommend on the subject: https://www.youtube.com/watch?v=7dmi1bsrsLk. That said, if you’re looking for something more substantial I’d recommend the work by Rasmussen, Mestre, and Nedergaard (2022).

Relationship to industry

It’s important to me that I preface this section by emphasizing that I’m not here to tell you that you’re doing things the right or the wrong way. Instead, I wanted to offer you some potentially relevant information that you might not have been aware of. That, and to tie things back to the beginning, explain what I meant when I stated I feel there is a valuable resource is being mistreated.

Our brains are the only ones we’ve got, and in today’s high-tech, fast-paced society, it’s incredibly easy to treat it as a second class citizen; even blame it for not working the way we’d like it to.

Each business or team has their own cultures, rituals, and status quos in place, that might very well be beneficial. However, there sometimes are benefits to taking a step back and asking whether they are indeed helpful, healthy, or necessary in their current state.

Sometimes long hours and trudging along while incredibly stressed is viewed as heroic, when in reality it can be damaging – I mentioned sleep fragmentation and chronic stress as major debilitators of brain waste clearance.

This isn’t meant to be catch-all – some people can get away with lower sleep. Instead, the point is to be aware of these things, and to be aware of industry standards, and where the two overlap for the better or the worse.

So take care of yourself, take care of your team, take care of your employees, and if you haven’t heard of or read the Lorax, by Dr. Seuss, I strongly recommend it – so with that I’ll conclude with a question:

What would the Lorax say?

References

Bohr, T., Hjorth, P. G., Holst, S. C., Hrabětová, S., Kiviniemi, V., Lilius, T., Lundgaard, I., Mardal, K. A., Martens, E. A., Mori, Y., Nägerl, U. V., Nicholson, C., Tannenbaum, A., Thomas, J. H., Tithof, J., Benveniste, H., Iliff, J. J., Kelley, D. H., & Nedergaard, M. (2022). The glymphatic system: Current understanding and modeling. iScience, 25(9), 104987. https://doi.org/10.1016/j.isci.2022.104987

Brodt, S., Inostroza, M., Niethard, N., & Born, J. (2023). Sleep-A brain-state serving systems memory consolidation. Neuron, 111(7), 1050–1075. https://doi.org/10.1016/j.neuron.2023.03.005

Chong, P. L. H., Garic, D., Shen, M. D., Lundgaard, I., & Schwichtenberg, A. J. (2022). Sleep, cerebrospinal fluid, and the glymphatic system: A systematic review. Sleep medicine reviews, 61, 101572. https://doi.org/10.1016/j.smrv.2021.101572

Deng, S., Hu, Y., Chen, S., Xue, Y., Yao, D., Sun, Q., Nedergaard, M., Wang, W., & Ding, F. (2024). Chronic sleep fragmentation impairs brain interstitial clearance in young wildtype mice. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 44(9), 1515–1531. https://doi.org/10.1177/0271678X241230188

Hablitz, L. M., Plá, V., Giannetto, M., Vinitsky, H. S., Stæger, F. F., Metcalfe, T., Nguyen, R., Benrais, A., & Nedergaard, M. (2020). Circadian control of brain glymphatic and lymphatic fluid flow. Nature communications, 11(1), 4411. https://doi.org/10.1038/s41467-020-18115-2

Hablitz, L. M., & Nedergaard, M. (2021). The Glymphatic System: A Novel Component of Fundamental Neurobiology. The Journal of neuroscience : the official journal of the Society for Neuroscience, 41(37), 7698–7711. https://doi.org/10.1523/JNEUROSCI.0619-21.2021

Jessen, N. A., Munk, A. S., Lundgaard, I., & Nedergaard, M. (2015). The Glymphatic System: A Beginner’s Guide. Neurochemical research, 40(12), 2583–2599. https://doi.org/10.1007/s11064-015-1581-6

Kroesbergen, E., Riesselmann, L. V., Gomolka, R. S., Plá, V., Esmail, T., Stenmo, V. H., Kovács, E. R., Nielsen, E. S., Goldman, S. A., Nedergaard, M., Weikop, P., & Mori, Y. (2024). Glymphatic clearance is enhanced during sleep. bioRxiv 2024.08.24.609514; doi: https://doi.org/10.1101/2024.08.24.609514

Rasmussen, M. K., Mestre, H., & Nedergaard, M. (2022). Fluid transport in the brain. Physiological reviews, 102(2), 1025–1151. https://doi.org/10.1152/physrev.00031.2020

The Picower Institute for Learning and Memory. (2023, November 1). Maiken Nedergaard at the MIT Aging Brain Initiative Symposium [Video]. YouTube. https://www.youtube.com/watch?v=7dmi1bsrsLk&ab_channel=ThePicowerInstituteforLearningandMemory

von Holstein-Rathlou, S., Petersen, N. C., & Nedergaard, M. (2018). Voluntary running enhances glymphatic influx in awake behaving, young mice. Neuroscience letters, 662, 253–258. https://doi.org/10.1016/j.neulet.2017.10.035