Here is how you dissect out a squid’s giant axon:
First, using a net, catch a squid (Loligo pealei
is what I have in mind here, but other species would be similar, no doubt) from the tank. It will not be pleased you have done this.
Next, grab hold of the squid in your left hand. That’s important because you are about to wield scissors, and any lefty will tell you that this is an absurd challenge using your left. The squid, at this point, remains unhappy.
The squid’s unhappiness is important because it will do one thing for sure that you want it to do, and it may do another that you don’t. The first is that it will continually extend and retract its head, leaving its “neck” (for lack of a better term) exposed, and the second is that it may shoot ink all over the place. To avoid ruining your day along with the squid’s (which, sorry, is already ruined), point its tentacles away from you. It will do a third thing, again for sure, that is incidental to your purposes — it will change from translucent beige to a deep, pulsating red. It advertises its unhappiness, whether you are in the market or not.
You are now holding a squid in your left hand, tentacles aimed in non-dangerous direction. You are holding it over a bucket; any normal bucket will do. You are also holding scissors in your right hand, waiting for its repeated head/neck extensions. You will now cut the squid’s head off.
Cutting the squid’s head off with scissors sounds a bit barbaric, but do not worry: it is worse than it sounds. After a decisive, rapid snip, the squid’s head, which includes its tentacles, will fall into the bucket with a satisfying/emetic splat, but that is not its final act. No, that head-and-tentacles combo has a good four or five more minutes in it, and it will use them. It writhes, reaches, grasps, extends, retracts, and otherwise ambulates around the bottom of the bucket, all the while with its large, lidless eyes occasionally glancing upward toward you, its own personal guillotine operator.
Once you have cut off the head, you may comfortably ignore the macabre scene playing out in the bucket’s recesses. Though it may appear to be trying, the head will not climb out in search of its killer (though I admit this may be one of those “past performance is no guarantee of future results” sorts of things). Cut down the length of the squid’s mantle, almost unrolling it into a flat near-triangle. The ink sac is now visible, a silvery oblong shape inside some other clear tissue; avoid cutting this, for obvious reasons.
Remove the internal organs, ink sac included, and the “pen,” a plastic-like spine running the length of the mantle; all this can join the head, now writhing its last, in the bucket. Cut a square-shaped piece of what remains from the central area of the mantle, and discard everything else; this last square of squid is where your final target actually resides. Pin it to a Petri dish, under a thin layer of water.
So far, you have conducted your near-Lecterian machinations in a tank room, most likely; it helps to be near where the live squid are housed, and, as mentioned, ink-related catastrophes are better kept away from the more delicate laboratory equipment. Now, bring your mantle-in-a-dish to a smaller lab room, where microscopes and tools made for precision-mutilation await.
From here on, you will dissect out the axon using one of those microscopes. Miniature scissors and fine-pointed tweezers will allow you to cut into the mantle toward the top (better scientists than I would likely use something like “distal,” “proximal,” or “anterior” to describe the location; I just remember that it was easier to start with the part farther away from me) of your square, and make a careful, just-below-the-surface incision running down the length of your prize, the giant axon.
Axons are pieces of nerve cells that help carry impulses away from the nerve’s body. As you might imagine, in humans — and most other animals — they are very small, invisible to the naked eye. Squid, however, have two giant versions: about a millimeter in diameter and, depending on the size of the squid, several centimeters in length. Your task in this micro-portion of the dissection is to cut carefully around this axon in order to remove it from the squid’s body. Once you have succeeded in doing so, resulting in a slimy, milky length of nerve cell dangling from your tweezers, pin the axon in another dish, again covered by water.
Congratulations. You now have a squid giant axon, likely with some of its intracellular properties still intact, ready for further study. This axon can be used to interrogate a variety of interesting specifics of neuroscience; researchers even earned the 1963 Nobel Prize in Physiology or Medicine
for research using squid axons that showed how action potentials propagate through nerve cells. But if you are me when I was 16 and 17, at the Marine Biological Laboratory
in Woods Hole, Massachusetts, you can now hand this off to the real scientists who will engage in that further study, because shit, what are you
going to do with this thing?
, instead of carefully injecting fluorescent beads into the axon and then viewing how they move along its length using an absurdly expensive confocal laser microscope, will maybe take a quick break, and then go back to the tank room to murder another squid. You will prove so adept at pulling giant axons out of squid that another scientist at the MBL will hire you, separate from this $12/hour gig (probably? This was 1997, so who knows) you've already got, to murder more
squid and pull out more
axons and then freeze them using absurdly-fun-to-play-with liquid nitrogen for later use and he will pay you by the centimeter of axon
, which in retrospect is an amazing metric by which to have earned some extra cash.
You will live in this world for two summers, when most teenagers are busing tables or washing dishes (which you did
do the summer before your first as Squid Enemy Number One, so you knew the difference), and you will realize later the conflicting set of messages it left you with: that science is boring, repetitive, incredibly specific and targeted; that science is fun, different, a unique way to spend one’s professional time.
You will, apparently, take these messages to heart, and essentially never let one of them win. You will sit on a fence in college, only abandoning physics for English when the math required outpaced your interest in keeping up with it. You will get a job in medical writing, then go to grad school for science journalism, because writing about science means you don’t ever have to focus as specifically as those squid researchers did, and you get to see the cool parts without all that work
And then you will start writing about how science is treated by politicians. And you will wonder, how did we elect these
assholes (not all-inclusive! Just, you know, the assholey ones) to give out money to NASA and NOAA, to regulate drug development and vaccines, to support basic biomedical research such as that done on the giant axon of Loligo pealei
And you will think, would it help these politicians to see that squid head writhing around in its bucket? Would seeing some of the practice of science, with its messiness and its attention to detail and its long, drawn-out march from one step to another until some usable answer is obtained — would all that help them understand just what it is they keep fucking up all the time?
You will be unsure of the answer. But, you will feel pretty good about saying — it couldn’t hurt.
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is a journalist, focusing on science and in particular its intersection with politics and policy. He has written for a wide variety of outlets, including the Washington Post
, and many more. His new book is entitled Not a Scientist: How Politicians Mistake, Misrepresent, and Utterly Mangle Science