Postural Muscle Tone depends on Norepinephrine

pattismith

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Optogenetic stimulation of the locus coeruleus noradrenergic neurons can increase wakefulness, and high-frequency stimulation decreases noradrenaline levels and produces loss of muscle tone similar to that seen in cataplexy.
We suggest that the noradrenergic system functions to couple the brain systems that control postural muscle tone and behavioral arousal state.
Postural muscle tone is potently suppressed during sleep and cataplexy. Since brainstem noradrenergic cell discharge activity is tightly coupled with state-dependent changes in muscle activity, it is assumed that noradrenergic drive on to somatic motoneurones modulates basal muscle tone.

However, it has never been determined whether noradrenergic neurotransmission acts to directly regulate motoneurone activity or whether it functions to modulate prevailing synaptic activity. This is an important distinction because noradrenaline regulates cell excitability by both directly depolarizing neurones and by indirectly potentiating glutamate-mediated excitation.
...
Our data indicate that exogenous noradrenergic drive does not directly affect spontaneous motoneurone discharge activity in anaesthetized rats; rather, it triggers postural muscle tone by amplifying prevailing glutamate-driven excitation.

Noradrenaline triggers muscle tone by amplifying glutamate-driven excitation of somatic motoneurones in anaesthetized rats - PubMed (nih.gov)

2008

A Noradrenergic Mechanism Functions to Couple Motor Behavior with Arousal State - ScienceDirect

2013

Illuminating the locus coeruleus: control of posture and arousal | Nature Neuroscience

2010

A good Postural Muscle Tone is needed for a good standing posture!

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Violeta

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Oh my goodness! I have been fighting bad posture since my teen years! I actually envy people who naturally have good posture. This would make so much sense because norepinephrine is involved in orthostatic intolerance, which I just realized I have this past fall. Thank you so much for this!

I need help with understanding this, though.
Especially as one who has horrible reactions to glutamate.

"The stimulatory effects of noradrenaline were unmasked and rapidly switched on only in the presence of glutamatergic transmission."

Would this apply to the glutamatergic transmission? If so, we are back to calcium channels again.

"A neuron sending a signal (i.e., a presynaptic neuron) releases a chemical called a neurotransmitter, which binds to a receptor on the surface of the receiving (i.e., postsynaptic) neuron. ... The increase in intracellular Ca2+ concentration triggers the release of neurotransmitter molecules into the synaptic cleft."

I guess so.

Physiological astrocytic calcium levels stimulate glutamate release to modulate adjacent neurons
https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC26999/
 
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pattismith

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Oh my goodness! I have been fighting bad posture since my teen years! I actually envy people who naturally have good posture. This would make so much sense because norepinephrine is involved in orthostatic intolerance, which I just realized I have this past fall. Thank you so much for this!

I need help with understanding this, though.
Especially as one who has horrible reactions to glutamate.
I took Duloxetine, a Norepinephrine/serotonine reuptake inhibitor, and I was amazed how much it improved my muscle tone, my posture and my muscle strenght!

It also greatly reduced my herniated cervical disc pain (together with iron deficiency correction)

I was not really aware that muscle tone was brain dependent before relying on myocytes' own energy power....


GABA also modulate this muscle tone...
The best model to learn about this central activation/deactivation is cataplexy.
 

Violeta

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I took Duloxetine, a Norepinephrine/serotonine reuptake inhibitor, and I was amazed how much it improved my muscle tone, my posture and my muscle strenght!

It also greatly reduced my herniated cervical disc pain (together with iron deficiency correction)

I was not really aware that muscle tone was brain dependent before relying on myocytes' own energy power....


GABA also modulate this muscle tone...
The best model to learn about this central activation/deactivation is cataplexy.
I have to say I am still simultaneously slapping my forehead and rejoicing in this revelation.

I do have some GABA for my husband, I will try some of that. I also had ordered some tyrosine and royal jelly for the BH4 issue, which looks like it's upstream from norepinephrine. Let me see what else I can find.

Thank you so much for taking the time to write about this.

Several things about raising norepinephrine have come across my path in the past week, which seems like a blessed coincidence.
 

pattismith

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Several things about raising norepinephrine have come across my path in the past week, which seems like a blessed coincidence.
Another interesting model to understand the symptoms associated with norepinephrine deficiency is a genetic disorder: Dopamine Beta Hydroxylase Deficiency...

Dopamine beta (β)-hydroxylase deficiency is a condition that affects the autonomic nervous system, which controls involuntary body processes such as the regulation of blood pressure and body temperature. Problems related to this disorder can first appear during infancy. Early signs and symptoms may include episodes of vomiting, dehydration, decreased blood pressure (hypotension), difficulty maintaining body temperature, and low blood sugar (hypoglycemia).

Individuals with dopamine β-hydroxylase deficiency typically experience a sharp drop in blood pressure upon standing (orthostatic hypotension), which can cause dizziness, blurred vision, or fainting.

This sudden drop in blood pressure is usually more severe when getting out of bed in the morning, during hot weather, and as a person gets older.

People with dopamine β-hydroxylase deficiency experience extreme fatigue during exercise (exercise intolerance) due to their problems maintaining a normal blood pressure.

Other features of dopamine β-hydroxylase deficiency include droopy eyelids (ptosis), nasal congestion, and an inability to stand for a prolonged period of time.

Affected males may also experience retrograde ejaculation, a discharge of semen backwards into the bladder.

Less common features include an unusually large range of joint movement (hypermobility) and muscle weakness.



Dopamine beta-hydroxylase deficiency: MedlinePlus Genetics