Go study this and master the vocabulary. Everyone is so familiar with our brains with their parietal lobes and sulci and ganglia, but do people ever stop to contemplate the cephalopod brain? Nooooo. And it’s pretty cool.
Possibly the most obvious difference is that the nervous system of most invertebrates develops ventrally, rather than dorsally, like ours. Imagine that your nervous system formed on the other side of your throat, so that as the brain expanded, it had to wrap itself around your esophagus.
23 comments
Skip to comment form ↓
rq
9 November 2012 at 8:26 am (UTC -5) Link to this comment
Being intelligent might kill you.
blf
9 November 2012 at 8:32 am (UTC -5) Link to this comment
What controls the lasers?
Gregory in Seattle
9 November 2012 at 8:41 am (UTC -5) Link to this comment
As I understand it, vertibrates developed upside down: most other species have their neural cord on their ventral side, where it is easier to protect by curling up.
jnorris
9 November 2012 at 8:44 am (UTC -5) Link to this comment
I see the cephalopod brain has an ant tunnel. Given there are no ants under the sea, this must have evolved while the cephalopods were land dwellers. Is this one of those evolutionary vestigial organs?
bbgunn
9 November 2012 at 8:50 am (UTC -5) Link to this comment
For me, that would come in handy at some of those ‘all you can eat’ buffets.
latsot
9 November 2012 at 9:10 am (UTC -5) Link to this comment
My optic stalk hurts :(
Snoof
9 November 2012 at 9:40 am (UTC -5) Link to this comment
So their retina is the right way around… and their _brain_ is not?
Are there _any_ animals with a nervous system that would pass a quality inspection?
adamarmstrong
9 November 2012 at 9:46 am (UTC -5) Link to this comment
I’d be worried that a large meal would cause brain damage.
Bronze Dog
9 November 2012 at 9:54 am (UTC -5) Link to this comment
I get used to a lot of cephalopod weirdness and now I discover this. I don’t think you’ll be running out of strange things about them to tell us.
Sastra
9 November 2012 at 9:57 am (UTC -5) Link to this comment
“Don’t think before you speak.”
I imagine there would be a lot of openings in the conservative movement for a person like that.
john
9 November 2012 at 10:06 am (UTC -5) Link to this comment
Nile catfish has a ventral spine. Can’t think of any other vertebrates, though flounders try to compromise, and so do humans in a different way. And please don’t respond that the Nile catfish is upside-down. That makes about as much sense as claiming that all humans are muslims, except for the apostates. That catfish is arguably the only vertebrate that is not upside-down.
TonyJ
9 November 2012 at 10:38 am (UTC -5) Link to this comment
As my 7-year-old son likes to say (he went to octopus camp at the Seattle Aquarium this summer): An octopus better be careful drinking a slurpee or it’ll get a really bad case of brain freeze!
PZ Myers
9 November 2012 at 10:46 am (UTC -5) Link to this comment
Uh, what? No! Like ALL vertebrates, the Nile catfish has a dorsal nerve cord, with a notochord (which is replaced by vertebrae) ventral to it. It has the standard anatomy. It would be extremely surprising to find a vertebrate that had completely inverted the fundamental developmental pathways in axis formation.
I think you’re confused by the fact that the Nile catfish lacks a dorsal fin and dorsal spines — the spiky pointy bony needles that brace a membranous fin and are sometimes modified into defensive structures. Not spines as in backbones, but spines as in fin rays.
hyperdeath
9 November 2012 at 10:52 am (UTC -5) Link to this comment
That’s just silly. Next you’ll be telling us that the nerve linking a giraffe’s brain to its larynx takes a 15 ft detour down its neck, so that it can loop around the aorta.
Ogvorbis: broken and cynical
9 November 2012 at 11:02 am (UTC -5) Link to this comment
I know some people who’s colon is wrapped around their brain. Does that count?
Gregory in Seattle
9 November 2012 at 11:31 am (UTC -5) Link to this comment
@Ogvorbis – No, because their brains develop in the normal position and migrate to the colon later in life.
Nick Gotts (formerly KG)
9 November 2012 at 11:37 am (UTC -5) Link to this comment
Well we’ve seen in the last few days that in the case of right-wing pundits, the brain is contained in a small pouch in the side-wall of the colon.
grumpypathdoc
9 November 2012 at 12:01 pm (UTC -5) Link to this comment
I learn something new every time I visit your blog, PZ. I missed this in comparative anatomy, way, way, back, but then cephalopods are notoriously rare in WV.
But then, I can’t resist it, cephalopods are almost thinking with their stomachs.
DLC
9 November 2012 at 2:41 pm (UTC -5) Link to this comment
At the risk of sounding like Mr Spock: fascinating.
Paulino
9 November 2012 at 4:04 pm (UTC -5) Link to this comment
PZ, the molluscan “brain” doesn’t wrap around the esophagus due to growth. Actually the pedal ganglia pair, that is ventral to the esophagus, and cerebral ganglia pair, that is dorsal, along with their correspondent commissures form a ring around it. In more active mollusks, that need more info-processing power, the ganglia tend to concentrate and fuse, forming a “brain”, more commonly called a nerve ring.
billydee
9 November 2012 at 7:34 pm (UTC -5) Link to this comment
I always get the post. buccal l. mixed up with the superior buccal l.
(What’s an l.?)
nathanaelnerode
10 November 2012 at 4:06 pm (UTC -5) Link to this comment
What I’m getting out of this is that cephalopods think *very differently* from us vertebrates. Have we done some MRIs to work out what parts light up during different types of thinking processes?
jayray
10 November 2012 at 10:07 pm (UTC -5) Link to this comment
It probably stands for Lobe.
I hope it stands for Laser.