Sebastian Seung, “Connectome”, 2012, Part Two (2).

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Abraham L. Kierszbaum & Laura L. Tres, “Histology & Cell Biology”, was the topic of an earlier blog post.

 Sebastian Seung, “Connectome”, 2012, was also the topic of an earlier blog post.

 

Here I Present: Sebastian Seung, “Connectome”, 2012, Part Two (2).  

Sebastian Seung’s discussion of the nematode (roundworm) in the book is the topic of this blog post.  Nematode (roundworm) is chosen over Annelid (segment-worm) as a “model organism”.   The chart BELOW shows the evolutionary levels that the two worms occupy at position #A  and position #B on the evolutionary tree.

Sebastian Seung is correct in stating that the nematode (roundworm) has only three-hundred-two (302) neurons (nerve cells).  Shown BELOW, the nematode (roundworm) consists of only seven (7) tissue-types.

ABOVE is the anatomy of an Annelid  (segment-worm), which is higher in the evolutionary tree than the Nematode (roundworm).

The important difference between the Nematode (roundworm); is that the Annelid (segment-worm) consists HEART & BLOOD VESSELS (shown in the diagram). This is a Circulatory System in the Annelid; but, no Circulatory System in the Nematode. 

 

Here I presented: Sebastian Seung, “Connectome”, 2012, Part Two (2).

SUMMARY.

Nematode (roundworm) has a nervous system of only three-hundred-two (302), neurons (nerve cells) that why it is a “model organism” in neuroscience.

COMMENT.

1.  Annelid & Nematode worms are composed of “Tissular Cells”, as these organisms are tissular. There are seven (7) tissue-types in the roundworm (nematode).

2.  “Anatomy” is a subject of  six (6) levels from:

– Population.

– Organism.

– Organ.

– Tissue.

– Cell.

– Molecule.

3.  Anatomical resolution at the Molecule level (level six) is the of study to select Nematode (roundworm) over Annelid (segment-worm) as Sebastian Seung discussed.

 Sebastian Seung’s book presented topics such as this for the general-reader, that was excellent.

 The feature image at the top of this blog post is the Circulatory System in the Human Brain (which is what the worm-model is used to study).  

The Nematode (roundworm) is shown BELOW has a tube-in-tube” body-plan.

The “tube-in-tube” anatomy of the Nematode (roundworm) is a model for Human Brain Capillaries.  This is a “permeate” from membrane of metabolites (shown BELOW). The intestine runs through the length of the Nematode (roundworm) and is equivalent to a Human Brain Artery.

The mapping of the “arthropod”  Fruitfly brain of one million (1,000,000) neurons (nerve cells) is currently being researched.   

Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts, & James D. Watson, “Molecular Biology of the Cell”, 1994 was the topic of an earlier blog post.