Growing older is different than I thought it would be. There are parts of it that I really relish. For one, I continually surprise myself – by what I know, and by what I don’t have a clue in the world about. Both of which I can generally freely admit without shame or blame. So one thing I am able to easily confess at this late date is … my own cluelessness, my own dumb-as-a-boardness (I actually mistyped “bardness” there momentarily🙂 before Auto-correct took over).
I’m also able to sit back in my fogeyness and appreciate my interest in how my brain and body work. I’m a self-taught brain teacher of middling knowledge. Sometimes my left brain attempts to flog me good because I’ve never had a living brain sitting out on a table in my laboratory funded by millions in National Science Foundation grants (actually, no laboratory neuroscientist has had one of those brains either – fortunately, for the owner – since most all brains sitting on lab tables are donated by dead people).
Nor have I spent years registering and reading brain activity on a computer screen from an fMRI or a Diffusion Tensor Imaging (DTI) scan (although I have witnessed a few; they’re kind of boring, actually, unless they’re connected to research you’re truly passionate about). In my older age, I’m much wiser to my bully left brain and the feel-bad thoughts it freely generates – less and less though, does it manage to get the drop on me.
Embracing Oldster Decline
I’m also able to meet more and more of oldster life as it arrives, both sweet and painful, in the present moment. This morning I turned to hang Bodhi’s leash on the coat tree near the front door and immediately felt a killer muscle spasm behind my heart, under my left scapula. I just stayed with it and alternated my attention on my breathing and the pain, breathing-pain, breathing-pain, until finally the pain simply stopped. Fortunately, the breathing continued. One day though, it won’t. I hope and expect to be as fully present as possible when that happens.
Only “fully present” today turns out to be roughly 14% less present than it was yesterday. Why? Because of some interesting recent foreign brain research. For the last dozen years or so, over and over I’ve encountered multiple claims in the literature that the brain contains roughly 100 billion neurons. That’s a nice, BIG round number. I never questioned either who counted them or how they did it. Some things you just take on faith. But not in neuroscience.
Testing Faith in Numbers
Well it turns out that a Brazilian neuroscientist, Suzana Herculano-Houzel decided she’d try to find the root reference for that 100 billion number. To both my and her surprise, she was unable to track it down. So she decided to do her own count using a newly developed method called isotropic fractionation. She rounded up four recently deceased adult male brains, turned them into a “fractionated liquid” – a kind of brain bisque – and then took representative samples from each homogenous pot of brain soup and counted the cells in each sample. Scaling up, she determined that the average human brain actually contains only 86 billion neurons – a 14% reduction from what we previously thought.
“Not one of the brains that we looked at so far has 100 billion neurons,” Herculano-Houzel disclosed. “Even though it may sound like a small difference, 14 billion neurons amount to pretty much the number of neurons that a baboon brain has, or almost half the number of neurons in the gorilla brain. So that’s a pretty large difference, actually.”
Large difference, indeed. I’d like to think the 14% I don’t really have mostly make up my baboon part. But there’s too much confirming evidence to the contrary! For example . . . my excitement over research involving things like how data-rich my poo is, or taking ear wax out of a good ear and sticking it into an infected bad ear to produce a cure, or by fecal transplantation as described by Emily Walker in her Slate article: The Enema of Your Enemy is Your Friend, I feel much closer to my baboon roots and to the 16 year old I used to be than any esteemed social neuroscientists! And did I mention that I also have much more fun in all my playful, glorious ignorance?