Ramblings on healthcare, medical education, and life with a spinal cord injury
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Category — The Brain

Exercising the Brain

One of the things I was always proud of when I was younger was the ability to adapt and pick up new things very quickly. Technology, theories, processes – whatever it was. I saw people generations older than me, and they had such difficulty with things like programming a VCR, or using a computer, or even a microwave. I chalked it up to a technology-related phenomenon, and ascribed it simply to the difference between growing up in very different ages.

Then as I got a little older, I found I had less patience for certain things. Things that, as a teenaged idealist, I would have gladly done the very long, very complicated way – because it was the “true” way to do something the way I wanted, rather than the shorter, quicker way that pretty much got me to the same endpoint. (For the geeks out there, compare using Gentoo and building everything from scratch, spending hours alone on something like glibc, compared to using a package management system and having things installed in seconds.)

I’ve often wondered whether or not differences between younger and older are generational, or are simply a function of changing brain activity over time. It’s made me worry that I too may someday succumb to those changes, although I always tell myself it’ll never happen. This thought process was again triggered this morning when I heard an older person (probably late 60s-early 70s) saying that he can’t be bothered to figure out technological devices anymore, and instead depends on a family member.

Are those differences a function of people having less patience for tasks that are (seemingly unnecessarily) overly-complex? Or are they a function of changes in brain function over time? And if they are related to changes in brain functioning, what can we do to prevent it? Is it related to the tendency to learn less as people age?

The brain, like many other things, falls under the “use it or lose it” umbrella. In my first year of medical school, a Ph.D. neuroscience researcher told me that, through his own studies, he found that newly-formed synapses can begin to degenerate if they are unused for only a few weeks. Now, this was relating to neuroplasticity and in the context of me forming new synapses by exercising. However during brain development and maturation (the so-called “critical period“), we form tons of new synapses. And during that time, if we are not actively using them, they degrade.

So how does that relate to age-related decline? Are we losing synapses, critical to thinking, if we don’t actively exercise the brain by continuing to think critically and learn? My instinct has always been that, yes, we do. And that the best way to ensure the brain continues to function at its highest possible levels is to never stop learning, and never stop thinking critically. And every time I think that, it makes me even happier that I’m in a field where my job will involve learning and critical analysis until the day I die. Or quit. Although I’m not sure which I expect to happen first. I’ve also wondered if this is all true, does it mean these age-related changes tend to be less pronounced in people who spend their lives in academic professions?

Today I did a little research on the matter, and came across an interesting article from JAMA, entitled “Neurobiological Changes in the Hippocampus During Normative Aging.” The hippocampus is critical to things like memory, especially spatial memory, and is often a focus of study with respect to aging. The study goes on to state that there is neither a great loss in the number of neurons in the brain associated with aging, nor is there a loss in the biological function of those neurons. What does change, quite significantly, is the synaptic relationships. In one region, a 24% reduction in the number of synapses was observed in older brains compared to younger, which correlated to a concomitant decrease in measured electromagnetic fields in the brains. There is some attempted compensation by the synaptic potentials being larger, but it doesn’t seem to be enough to make up for the losses.

So the number of synapses declines, so what? Can we stop it? Do we really lose it if we don’t use it? It turns out, studies have shown that synapses are strengthened by repeated use, a process we now refer to as long-term potentiation, which has separate phases: induction, and early and late maintenance. LTP does change with age, decaying faster in the older brain, and those changes appear to be more pronounced in cases where it is used less. So it does become more difficult as the brain ages to form new memories, and it becomes easier to forget things. And that becomes even more significant when we don’t use our brains as much.

But that’s just a tiny point in a much bigger discussion, and certainly one can’t abstract synaptic changes in one specific region of the brain to the entire organ. But it’s nonetheless fascinating. People who become stagnant in other areas of life, progress on a weightlifting or exercise routine for example, often tout changing things up as a way to get past a plateau. Challenge oneself, the theory goes, and you force your body to grow and adapt to something new, rather than depending on muscle memory. If you get bored on your routine commute, you might change things up and go a different way.  You see new scenery and aren’t as much on auto-pilot.

Why not the same with the brain?

Challenge yourself to read about, learn about, think about, or try something new. Make it a habit. You might find that you even get better at doing the things that are at this point routine.

That’s what I’ll be doing to help ensure this gelatinous mess inside my skull keeps working to the best of its abilities. Or at least, the ones I’ve still got left.

February 26, 2013   2 Comments