I noticed a new paper today. Which set me thinking.
It is heavy going reading these things. Don't feel in the least surprised if it all goes above your head - by far the majority is miles above mine! 
And it is very largely me speculating and joining ideas I have read. Quite possibly entirely wrongly.
But if it does makes any sense, could we be getting somewhere towards understanding pain - possibly such as in CFS/ME and even myofascial trigger points? As well as the many pains reported by so many even without any of those diagnoses.
New mechanism of pain control revealed
Date:
November 25, 2020
Source:
Kyushu University
Summary:
Researchers have identified a unique population of astrocytes in the dorsal horn of the spinal cord of mice that produces pain hypersensitivity when activated by neurons carrying signals down from the brain. The findings indicate that the role of descending neurons in controlling spinal pain transmission is not limited to suppression and point to this group of astrocytes as a new target for enhancing the effect of chronic pain treatments.
Later, in the main paper, it says:
It was previously assumed that certain sensory neurons only transmit pleasant tactile sensations, while other specializes to transmit pain. During chronic nerve pain, normal touch can cause pain, but how this happens has remained a mystery. Scientists at Karolinska Institutet have now discovered that a small RNA molecule (microRNA) in sensory neurons regulates how touch is perceived. Upon nerve damage, levels of this molecule drop in the sensory neurons, which results in raised levels of a specific ion channel that makes the nerve cells sensitive to pain.
sciencedaily.com/releases/2...
The idea that normal touch can cause pain sounds as if it is, potentially, a (or even "the") mechanism behind the still unexplained allodynia. Where the slightest brush (literally with a soft brush or a feather), which should hardly be noticeable at all, ends up causes significant pain.
The other thing that struck me was that thyroid hormone is one of the factors deeply involved with microRNA.
(One example paper: ncbi.nlm.nih.gov/pmc/articl... )
Now, just think, some astrocytes are specifically involved in T4 to T3 conversion within the brain. Is it possible the newly discovered dorsal horn astrocytes convert T4?
Thyroid hormone and astrocyte morphogenesis
Andréa Gonçalves Trentin 1
Affiliations
• PMID: 16648287
• DOI: 10.1677/joe.1.06680
Abstract
Astrocyte cells clearly play a role in neural development, but nowadays their total action is seen as a far wider one. Recent findings consider them as stem cells, involved in the control of most facets of functional neural networks. Astrocytes play a central role in thyroid hormone metabolism in the brain, being the principal transporters of thyroxine from the blood, responsible for its conversion to 3,5,3'-triiodothyronine and hence supplying the neural tissues with the biologically active form of the hormone. Specific thyroid hormone transporters play an essential role in this regulatory system. The presence of thyroid hormone receptors has been demonstrated in cultured astrocytes. Furthermore, thyroid hormone regulates several aspects of astrocyte differentiation and maturation, including the production of extracellular matrix proteins and growth factors, and thus controls neuronal growth and neuritogenesis. Therefore, astrocytes are currently suggested as important mediators of thyroid hormone in neuronal development.
pubmed.ncbi.nlm.nih.gov/166...
Please feel free to point out how wrong-headed I have been.
