Note (12/2015): Hi there! I'm taking some time off here to focus on other projects for a bit. As of October 2016, those other projects include a science book series for kids titled Things That Make You Go Yuck! -- available at Barnes and Noble, Amazon and (hopefully) a bookstore near you!

Co-author Jenn Dlugos and I are also doing some extremely ridiculous things over at Drinkstorm Studios, including our award-winning webseries, Magicland.

There are also a full 100 posts right here in the archives, and feel free to drop me a line at with comments, suggestions or wacky cold fusion ideas. Cheers!

· Categories: Biology
What I’ve Learned:

Glial cells: you're gonna think lightning; you're gonna cogitate thunder!
“Glial cells: you’re gonna think lightning; you’re gonna cogitate thunder!”

We can’t all be the star of the show.

Think about it — sports tournaments don’t nominate Most Valuable Plethora. Only one actor in a movie gets to be the headliner, pretty much by definition. And no matter how smart those “meddling kids” are, it’s still the Scooby Doo show.

(And don’t you forget it, Fred, ya scarf-wearing frat-boy bossypants.)

Still, there’s nothing wrong with working in the background. Playing cheerleader for the star. (But not head cheerleader, of course.) Being the best darn supporting actor you can be. That’s true everywhere in life — even in our own brains. Most people think of their skulls being filled — or mostly filled, in some cases — with neurons, the cells we use to think and add and learn and compose bawdy limericks about buckets.

But that’s not quite true. Actually, our headbones are only half — or mostly-half — full of neurons. The other half are filled with something called glial cells, which are not neurons, but do help the neurons do their various jobs. And sometimes more.

Consider Rocky Balboa.

(I know. Not a name often associated with matters of the brain, for good reason. But stick with me here; I can make this work.)

Rocky was, of course, the star of the Rocky movies. Sure, he’d get his bloodied butt handed to him for a while by Ivan Drago or Mr. T. or that shifty CIA dude from Predator, but then he’d train up, grunt some stuff and punch them stupid. So it’s his name on the marquees.

But he didn’t do it alone. His trainer Mickey was there to help him — keep him on track, give him advice and yell gibberish at him every once in a while.

That’s what the glial cells in the brain do, more or less, for their diva neurons. First, the glial cells provide physical support and structure. You can’t box on a playground; you need a gym. So the glial cells make the gym our neurons work out in.

And some types of glial cells wrap around neurons, leaving something called a “myelin sheath” behind. This is like strapping the gloves and shoes onto a boxer — the myelin makes neurons quicker and more efficient. Real float-like-a-butterfly stuff.

But that’s only the beginning; glial cells also provide nutrients for neurons. I don’t know what kind, exactly — oxygen, probably, and vitamins; maybe a glassful of raw eggs on heavy logic days? That sounds right.

Another thing glial cells are important for is keeping neurons away from each other. Like professional fighters — especially Hollywood movie professional fighters — neurons like to get in each others’ faces. Or synapses, I guess. But the point is, they’ll talk trash at each other — unless the glial cells get in there and keep them apart. Because you’ve got to save all that cerebral violence for the ring. Or the SATs.

And there’s more; glial cells help neurons by keeping out distractions. Like infections, for instance. Or dead cells. Sleazy fight promoters. Talia Shire, maybe; I don’t know who’s banging around in your head. But whatever butts in, the glial cells boot it out, so the stars can shine. Sting like a bee, baby.

And just like Mickey — a former fighter himself — there’s evidence that some glial cells might even do their own mental “boxing” in the form of releasing transmitters, just like neurons. Not bad for a few billion has-beens and some never-weres, eh?

So the next time you’re thinking about thinking, or anything brains do, give a nod to the glial cells. Neurons are great and all, but without their glia, they’d be a bunch of bums. Bums, Rock! Bums!!

Image sources: The MedSchool Project (glial cell), Real Truth About Life… (frowny-faced Fred), Robakers (Mickey lightning, Mickey thunder), Monster’s Movie Mayhem (Rocky on top)

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· Categories: Biology
What I’ve Learned:

DNA polymerase: come with me if you want to replicate.
“DNA polymerase: come with me if you want to replicate.”

DNA polymerase is an enzyme present in every living cell. Hay cells, jay cells, even George Takei cells. Oh, my.

In these cells, DNA polymerase has one job — just one job — and it’s both the easiest and hardest job on Earth. Biology textbooks would tell you that job is to “replicate” the cell’s genetic material, reading and copying DNA so when the cell splits, both new cells contain a full set of genes.

And that’s true, in the same way it’s true that Tito Jackson recorded twenty Jackson 5 records. He did — but he had a hell of a lot of help.

It’s the same with DNA polymerase. It plays an important role in replicating DNA, sure, but it’s led to the job site by an entourage of support proteins, propped into place, and prompted for its lines. Each bit (or “base”) of DNA to be copied is a cue, and it’s DNA polymerase’s job to add the right complementary base in response. There are four different kinds of bases, so it only has four lines to remember.

This is why DNA polymerase’s job is the easiest in the world. It’s treated like a star. It gets driven to the set, carried to the stage, and it barely has to study a script. It just reads a cue and delivers the right line, out of four choices. It’s the gig of a lifetime.

Actually, I imagine it’s a lot like Arnold Schwarzenegger’s life these days. He probably does the odd public appearance for pocket change, followed around by a gaggle of handlers. They’d behave like the DNA replication helpers — getting him to the podium, making his hair look nice and prompting him for the appropriate line:

If it’s a Terminator convention, he’ll say: “I’ll be back!

At a children’s event: “It’s not a tumah!

At a GOP fundraiser: “I’m the Governator!

For a crowd of Predator fans worried about Anna: “Get to da choppa!

So wherever he goes, a flunky whispers into his ear: “Terminator”, “children”, “GOP” or “Anna”. And Arnold gives the proper response.

(Maybe the flunky even shortens it to one-letter codes: T, C, G and A.

Aw, yeah. You biochemical geneticists see what I did there.)

So DNA polymerase’s job is simple — as easy as a T-800 following a four-path if-then logic loop. Which is to say, it’s easy to do once. Even a few times a week, a la the former-Governator.

But there’s the rub. Human DNA polymerase reads and matches a DNA base about fifty times per second.

(E. coli polymerase is even faster, around one thousand matches per second. If you can picture a bacterial Arnold Schwarzenegger, moving at twenty times the speed. Hasta la nightmare, baby.)

That’s why DNA polymerase has the hardest job in the world. Our genomes are three billion bases long, and in rapidly-dividing cells like skin or hair or stomach lining, the replication never stops. One mismatch could create a mutation that kills the cell, or cause out-of-control growth into cancer. (“Then it IS a tumah!”) Yet our DNA polymerases are extremely accurate, mismatching less than once every ten million bases — and they can even correct their occasional mistakes.

Which is good news for us. It’s no big deal if an aging actor accidentally tells a bunch of six-year-olds to “get to da choppa!“. But our inner Ahhhnolds get their lines right — all the time, nearly every time, and without the help of cue cards. That’s why if it bleeds… we can find DNA polymerase inside it.

Actual Science:
How Stuff WorksDNA replication
The OncologistThe molecular perspective: DNA polymerase
WileyDNA replication
Asian ScientistDemystifying Rule-Defying DNA Polymerases

Image sources: Vanderbilt University (DNA replication), Fanpop / Michael Jackson (Jackson 5), Screening Notes (“Tumah!”), New England Biolabs and TalkBacker (polymerase T-800)

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