I just finished another quarter at Oregon State University but it wasn’t without weeping, whining, and wailing. It wasn’t that the material was difficult to master, it was just that I had spread myself so thin by taking too many classes and because of one other fact that has hit me hard this year – I’m getting old. I had been fearing the getting old part of life for quite a while but it was only fear. I didn’t feel any older mentally or physically. Well, at age 45, I feel it. I’ve officially gone over the hill and I’m cruising on down in a mobility scooter with hair, teeth and thin dendritic spines (I’ll get to this in a bit) falling out along the way.
School was never difficult for me when I was younger. I didn’t freak out over tests. Heck, I barely had to study for them, not because I was super smart but because I remembered most of what the teacher said during lectures and pretty much everything I read. Well, those days are over. If I do well on a test, it’s because I’ve labored over the material for days trying to stuff bits and pieces of information, like a frantic squirrel burying nuts in the fall, into the parts of my brain that are still functioning. I try to compensate by learning in different ways – by vision, by sound, by reading, reenacting, meditation, Gregorian chants, and finally “God, if you help me pass this test I’ll stop bugging you about world peace and affordable cable television service.”
All of this got me thinking, just how bad does it get? What is happening to my brain as I age? Am I doomed? Well, I learned that I’m doomed in some ways, but not-so-doomed in others.
In a fascinating study by John Morrison and Mark Baxter on the aging brains of rats, our cousins, it was discovered that the effects of aging differs greatly between brain regions. The difference is in the plasticity of the two different types of dendritic spines, which are little protrusions on the dendrites of neurons that help transmit electrical signals. There are thin spines and shorter thicker ones. If you think back to your high school biology class you probably remember how neurons work well enough to visualize the firing of electrical pulses across synapses. And luckily, even if you’re old like me, you can still remember this for a good reason.
Synapses of the prefrontal cortex seem to take a hit as we age due to nearly a 50% loss of thin dendritic spines in this region. So what does this mean? Well, the smaller thinner spines are associated with learning and remembering new information, while the shorter spines are associated with things we learned years ago. Losing the thin spines makes it more difficult to remember new stuff. Apparently, it’s really hard to teach an old dog new tricks because he’s lost a lot of his thin dendritic spines. I’ve really simplified the study and probably gotten half of it wrong since it’s new information but well, I’m getting old.
Anyway, as we age, we usually remember life events of our youth quite vividly but then have trouble remembering where we parked our car 10 minutes ago. It can get kinda scary not remembering things like that. So, is there any silver lining to all of this? Well, if you write blogs about your youth, yes! If you like telling your grandchildren stories about the good ole days, yeah. If you want to remember your grandchildren’s names, maybe not so much. But not all is lost.
We don’t completely lose the ability to learn new information. It just might become more difficult to do so, which kinda stinks. But once we’ve really learned something and held on to that information for a little while, we don’t forget it. Even if we think you don’t remember algebra, it’s amazing how quickly it all comes back to us when exposed to it again.
So, for me taking a bazillion classes at one time is a really dumb idea. I have to spend more time on learning than I used to but I still learn. I’m not drooling out of the corners of my mouth yet.
Morrison, John H., and Mark G. Baxter. “The Ageing Cortical Synapse: Hallmarks and Implications for Cognitive Decline.” Nature Reviews Neuroscience Nat Rev Neurosci, 2012. doi:10.1038/nrn3200.0