The Cephalopod Comparative Neuroscience Thread

[neurobadger]

I thought it might be a good idea to start a thread like this.

Cephalopods, of course, are the only invertebrate example of an animal with a relatively complex brain which is organized very differently from ours and a brain-body mass similar to that of birds and mammals.

There's been much written on cephalopod behavior and neurobiology per se, but I'm not sure how much we've drawn out of comparisons with vertebrate brains.

One thing I can see from looking at schemata of various behavioral pathways in the cephalopod brain, and which I know Bernd Budelmann among others has discussed before, is that the cephalopod brain is not the hierarchically-organized brain that the vertebrate brain is, and each anatomical lobe is more bound to the others for a variety of functions.

In addition, it strikes me as significant - I'm not sure how - that they have a complex brain but no spinal-cord-type structure (I don't think the commissure linking the arms or the various large nerves and giant axons going to each ganglion count either).

At this point I'm sort of thinking aloud, but I'd like to start a discussion on this.

[OB]

Well, as a first off remark, cephalopods would hardly benefit from a spinal chord analogon, given their body plan; no complexity to their stance, movement and defying of gravity? What does amaze me, however, is the uncanny perception when seeing an octopus explore its surroundings, of each individual arm possessing a level of "free will" close to being interpreted as being of "a mind of its own". There must be feedback loops that only reach the central ganglia in a secondary fashion, I have no doubt. Yet, I am no neuroscientist, so my interpretations are "informed layman's", at best.

[tonmo]

Agree neurobadger, great thread to start!


There must be feedback loops that only reach the central ganglia in a secondary fashion, I have no doubt.
This has been reported as fact, but I don't have the reference.

[tonmo]

Here (http://www.eurekalert.org/pub_releases/2001-11/oonr-bba112601.php) is a reference to a study led by Tom McKenna which alludes to this. Interesting that this is from 2001, and just a few weeks ago a robotic octopus arm has indeed been developed!

[DWhatley]

Peter Godfrey-Smith (TONMO PGS - with a new avitar :grin:) (http://www.tonmo.com/forums/showthread.php?18734-Octopus-living-in-groups-and-more-stuff&p=166223&viewfull=1#post166223) has also been intrigued with this notion and will hopefully be doing some work on the subject (and give a talk at TONMOCON IV) this next year.