Re: Re: TO TERAHERT/Donna/Dolores

[Guest guest]

Hi, Dolores,

I am not sure what you mean, but Donna's explanation at the most

basic level seems correct to me. Lower motor neurons are those that

instruct the muscles to perform in a certain manner with those

instruction originated in the brain. Generally, there is little or

no involvement of the lower motor neurons in PLS. The problem is

that the upper motor neurons within the brain and spinal cord are

damaged or destroyed and therefore cannot carry the signal to the

connection (synapse) to the lower motor neurons.

In doctor speak from " Primary Lateral Sclerosis -- A heterogeneous

disorder composed of different subtypes? (Zhai et all, 2003):

" Preservation of the startle reflex in PLS demonstrates the integrity

of reticulospinal tracts, and supports the assertion that PLS

selectively affects corticospinal and corticobulbar systems " .

(Pringle, et. all)

Don