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Do benzodiazepines act on motor neurons outside the CNS ?

Motor neurons are affected by BZs.

By the way, that Wikipedia entry is wrong -- there are motoneurons in the brain. The cranial nerves originate in the brainstem.
 
That didn't clarify much. I can put it this way: are there motor neurons outside the central nervous system, or do BZs affect motor neurons in some way that is not related to the action of BZs in the brain ? More or less, direct action on nerves outside the CNS ?
 
I thought that BZDs had activity on spinal cord neurons?
 
Kdem said:
That didn't clarify much. I can put it this way: are there motor neurons outside the central nervous system, or do BZs affect motor neurons in some way that is not related to the action of BZs in the brain ? More or less, direct action on nerves outside the CNS ?
Click to expand...

The are effectively no differences between motor neurons in the spinal cord and those in the brainstem, including BZ sensitivity. It just so happens that some motor neurons are in the brain and some are in the spinal cord (both are part of the central nervous system).

In other words, there are motor neurons located outside the brain, but there are none outside of the central nervous system.

EDIT: One complicating factor RE your question is that there is a peripheral BZ receptor that is not associated with the GABA-A channel. It used to be called the peripheral BZ receptor, but it is now known as the translocator protein (TSPO). TSPO is found in mitochondria and involved in steroid synthesis. The interesting thing is that TSPO controls neurosteroid synthesis (some neurosteroids act as GABA-A positive allosteric modulators and have anxiolytic effects), so TSPO ligands can actually produce anxiolytic effects. TSPO is a target of diazepam and other BZs, so technically it is a BZ binding site in the periphery.
 
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serotonin2A said:
Motor neurons are affected by BZs.

By the way, that Wikipedia entry is wrong -- there are motoneurons in the brain. The cranial nerves originate in the brainstem.
Click to expand...

Sero, by the flanges of Zeus' silvery lined cloud toga! Is it not easier and better than wasting your effort conveying to just one person that "WP is wrong on such & such account" when you could expend that same amount of typing energy and source the act of *correcting* WP itself so *all* whom see it shall see what is correct?
 
serotonin2A,

'motor neurons in the spinal cord and those in the brainstem'

While there are some elsewhere (wiki:Upper motor neurons are motor neurons that originate either in the motor region of the cerebral cortex) , I'd like to focus on the brain stem and spinal cord.
All high potency benzos have a high affinity (right phrase?) for the brain stem. Much more so than low or medium potency benzos.
The same goes for the spinal cord, at least that's the case for clonazepam.

So, my thinking is that this drug has a relatively strong effect on motor neurons. And that all of this is, essentially, within the brain. Except for any tension/state of the muscles. Correct ?

And as a side question: are there any drugs that act selectively on these neurons, without acting on other neurons elsewhere ? (most dopamine agonists would affect these neurons, but as I understand they are not selective)
 
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