About this article
This article derives directly from the Wikipedia article of the same name (version of 23 July 2013), which is about 90% my work. (I contribute to Wikipedia using the name Looie496.) After moving the article here, I have extensively copy-edited it, and also removed the sections on Pathology and Development, as peripheral to the focus of Scholarpedia. (Also development is a weak area for me, so I wasn't enthusiastic about the quality of the material in that section.) I plan to add a bit more material to the section on Intrinsic Pattern Generation, given that that is a focal area for Scholarpedia. William Skaggs 20:09, 23 July 2013 (UTC)
Review by Paul Katz
"All other types of animals, with the exception of a few types of worms, have a nervous system containing a brain, a central cord (or two cords running in parallel), and nerves radiating from the brain and central cord. The size of the nervous system ranges from a few hundred cells in the simplest worms, to on the order of 100 billion cells in humans." This is not true. Echinoderms, which are deuterostomes, have no "central nervous system". See:
- L. L. Moroz. On the independent origins of complex brains and neurons. Brain Behav.Evol. 74 (3):177-190, 2009.
- R. G. Northcutt. Evolution of centralized nervous systems: Two schools of evolutionary thought. Proc Natl Acad Sci U.S A:10626-10633, 2012.
- Thanks, I have fixed that sentence. The Northcutt paper doesn't actually discuss that specific point as far as I can see, but I'm glad you cited it anyway, because I wasn't aware of it and it is very nice. Incidentally, if you have any inclination to make direct changes to the article, I hope that you will feel free to. Regards, William E. Skaggs 15:41, 31 July 2013 (UTC)
The figure showing a "bilaterian" body plan is misleading because it has a dorsal nerve cord. That is only found in chordates. Ecdysozoa (insects and crustaceans) and annelids have ventral nerve cords. --Paul S. Katz 20:06, 2 August 2013 (UTC)
- Point taken (and that's explained in the article), but it seems to me that a figure of this sort will be useful to readers. Would it suffice to explain the variations in the figure caption? William E. Skaggs 20:58, 2 August 2013 (UTC)
"Many evolutionary biologists believe that the generic form of the bilaterian central nervous system is inherited from the so-called "Urbilaterian" — the last common ancestor of all existing bilaterians — but there are some who believe that the evidence favors parallel evolution in separate lines (Northcutt, 2012). Rather than saying "Many...believe" cite a paper. Also, "belief" is irrelevant. State data, hypothesis, and theory, not belief. --Paul S. Katz 20:06, 2 August 2013 (UTC)
- The intent was to cite the Northcutt paper for both sides, since he discusses both points of view. I'll work on this (although I don't think it would be good to get too far "into the weeds" in this article. William E. Skaggs 20:58, 2 August 2013 (UTC)
It seems more logical to have the Function section follow the cells section because it is lower level of analysis than the overall organization of the nervous system. So, after introducing neurons in the Cells section, you can talk about neurons and synapses right away and then simple circuits.
- That makes sense, now that you have broken the "Structure" section into two parts. I won't make the change instantly (in case you happen to be editing right now), but I'll do it shortly. William E. Skaggs 18:20, 5 August 2013 (UTC)