Talk:Upper motor neuron

In

In the text I have, Neuroanatomy Text and Atlas, by John H. Martin, the glossary defines "motor neuron" (without either adjective "upper" or "lower") as a neuron that synapses outside the CNS either on muscle or on an autonomic ganglion. Thus "upper motor neurons" is a non-literal phrase, i.e. they're not motor neurons.

Btw, "motor neuron" and "motoneuron" are both acceptable, and mean exactly the same thing, afaik. But the Wikipedia article is at "motoneuron". dsws 16:17, 14 December 2005 (UTC)

• Your text is wrong. Upper motor neurons are spread throughout the CNS. Hell, lower motor neurons are inside the CNS. M1 Betz cells are upper MNs, the cingulate has upper MNs for autonomic functions, and anterior horn cells--the cells that directly create the neuromuscular junction, are within the anterior horn of the spinal cord, which is also CNS. That phrase is so incorrect that it would be worth writing the editor. As for the location of the wikipedia article, since "motor neuron" and "motoneuron" are synonymous, the main article has to exist at one or the other, right? So why not at "motoneuron" with a redirect there from "motor neuron"? It amounts to the same thing. Semiconscious 21:37, 15 December 2005 (UTC)

While this article is short, it contains all the important overview information on a general class of neurons and gives links to more specific information. As such, I've removed the stub tag. mcain (talk) 23:47, 29 April 2008 (UTC)

UMN

hi, when one types in 'UMN' it redirects to university of minnesota. if someone could put in a direct link for 'UMN' or a disambiguity page that'd be great. I don't know how. blahblax (talk) 21:00, 30 April 2008 (UTC)

Done: UMN --Arcadian (talk) 01:02, 1 May 2008 (UTC)

Final common pathway definition seems wrong

The text states.."the final common pathway, that is, any motor neurons that are not directly responsible for stimulating the target muscle." This seems quite wrong! To quote Sherrington, the originator of the term " The α-motoneuron is the final common pathway on which all efferent impulses from the CNS converge". See also the Wikipedia Neural_ensemble page. The α-motoneuron is the motoneuron which directly innervates a muscle. This seems contrary to above quote. Should we change the underlined text to "the final common pathway, that is, the alpha motoneurons which directly innervate the target muscles

Also, http://www.medterms.com/script/main/art.asp?articlekey=33871 defines an upper motoneuron as originating only in the cerebral cortex. I'm not expert enough to know if this is really the case. Here is another page which discusses all components of the motor pathway - http://www.csuchico.edu/~pmccaffrey/syllabi/CMSD%20320/362unit10.html. Another one http://pathology.mc.duke.edu/neuropath/nawr/motor-systems.html - which states "The upper motor neurons reside in the precentral gyrus of the frontal lobe also called the "motor strip". That is the cerebral cortex only.

The last link also had some interesting, possibly relevant information..."These upper motor neurons are arranged in a stereotypical fashion. Neurons which control movements of the face and mouth are located near the Sylvian or lateral fissue and neurons which control the muscles of the thighs and legs are located near the medial longitudinal fissure and within the central sulcus.

Many textbooks illustrate this phenomenon graphically using a distorted human figure called Homunculus. The homunculus has very large face and mouth because there are many upper motor which innervate these parts of the body." This link shows the humunculus - http://www.psywww.com/intropsych/ch02_human_nervous_system/homunculus.html. I'm not sure if there is a copyright-free version. It was originally published in 1950 (Penfield & Rasmussen. The Cerebral Cortex of Man. Macmillan, New York, 1950). The copyright was renewed by Rasmussen in 1978, but Macmillan gives permission to use the image in some instances.QuietJohn (talk) 06:53, 1 June 2010 (UTC)