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

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

Memorializing a Gift in Death

One of the quintessential medical school experiences is gross anatomy. It’s one of the things people frequently ask about, and it’s possibly the one single experience that causes the most apprehension amongst newly-minted students. That first exposure to a cadaver is one that nobody will ever forget. Unzipping the protective vinyl bag, curling back the large sheets of plastic, and being confronted with the somewhat rubbery skin of somebody’s embalmed remains is at once both intimidating and awe-inspiring.

We’re first instructed to locate structures that can be felt externally, which begins to ease the transition to an increased comfort with the person who will teach us most about the structure of the human body. Feeling skin and bony structures, cool to the touch, is a good way to start. Eventually we must pick up a scalpel and make the first incision, opening the layers of skin that, up until now, have been all many of us have had any kind of close contact with on another human being.

Stories often circulate of the occasional student passing out upon their first experience in gross. Others may become light-headed or need to take a break. It goes to show how significant this experience is in the many rites of passage in medical school. Nobody in our lab fainted, although I’m sure there was some apprehension that was not vocalized – we were all new to each other at that point in the year, and I’m sure some were guarded.

Often, the apprehension that precedes one’s first foray into the gross lab is gone shortly after that first experience. Replaced instead by a growing familiarity and sense of purpose, and the realization that there is nothing to be intimidated by. Our purpose is clear: we are there to learn, and that is what we do as time goes on.

While we are told the age and cause of death of these, our first patients, we are not told their names. The process is intended to be anonymous, to ensure the respect and dignity due the donors and their families. So instead, many students name the cadavers. These were people who led full lives, and giving them a name, rather than just saying “our body,” helps to make the whole process more personal. These aren’t animals or science experiments we’re peering into, they’re people. I’ve worked in two separate anatomy groups, in different classes, and have learned a great deal from both Alfred and Herman.

Along with the names sometimes come stories of the lives people led. Alfred had tattoos that appeared to be of a military origin, so given his age, we came up with stories of him flying planes in the Korean War. And things he had done since then. Alfred led a good life, was a good man, and had some incredible experiences.

A few days ago, Case held a memorial service for the families and friends of those who donated their bodies to our education. These were people who chose not to be buried or cremated, but instead to have their remains preserved and then torn apart by young, eager students. People who, even in death, have continued to give. One can only imagine that in order to bequeath such a donation, the donor must have been incredibly selfless.

Despite looming end-of-year and board exams, a lot of the students came to the service to honor and remember those who had died, and convey our gratitude to the loved ones who were not able to bury those they cared so much for. Seeing those people, after spending an entire year in the lab, was truly stirring. If those who lay on our tables had not been real enough before, they could not be more so now. The lives of those we memorialized had ended, but their spirit continues to live on, through the people they loved, and now, through us and through every patient we will be able to treat because of what we learned from them. Seeing the attendants of the service was every bit as memorable and humbling as that first step into the lab. Probably even more so.

As my first year of medical school draws to a close, I think back on how much I have learned scrutinizing Alfred and Herman. This experience is neither replaceable nor quantifiable. Every time I locate the anterior scalene, palpate the sternal angle, examine a radiograph, or dissect the connective tissue around a mass or vessel, it will only be possible because of what I have learned and practiced in gross. Every patient I treat, every student I teach, every patient those people treat, and so forth. It quickly becomes clear just how exponential the reach becomes.

So to Alfred, Herman, every other anatomical donor, and all of those who have sacrificed so that we may learn, I thank you with all my being. In death, you continue to live on and have single-handedly touched and benefited more lives than any of us could ever imagine.

May 18, 2010   1 Comment