Inflammation in dorsal root ganglia after peripheral nerve injury: Effects of the sympathetic innervation

Following a peripheral nerve injury, a sterile inflammation develops in sympathetic and dorsal root ganglia (DRGs) with axons that project in the damaged nerve trunk. Macrophages and T-lymphocytes invade these gan- glia where they are believed to release cytokines that lead to hyperexcitability and ectopic discharge, possibly contributing to neuropathic pain. Here, we examined the role of the sympathetic innervation in the inflammation of L5 DRGs of Wistar rats following transection of the sciatic nerve, comparing the effects of specific surgical in- terventions 10–14 days prior to the nerve lesion with those of chronic administration of adrenoceptor antago- nists. Immunohistochemistry was used to define the invading immune cell populations 7 days after sciatic transection. Removal of sympathetic activity in the hind limb by transecting the preganglionic input to the rele- vant lumbar sympathetic ganglia (ipsi- or bilateral decentralization) or by ipsilateral removal of these ganglia with degeneration of postganglionic axons (denervation), caused less DRG inflammation than occurred after a sham sympathectomy. By contrast, denervation of the lymph node draining the lesion site potentiated T-cell in- flux. Systemic treatment with antagonists of α1-adrenoceptors (prazosin) or β-adrenoceptors (propranolol) led to opposite but unexpected effects on infiltration of DRGs after sciatic transection. Prazosin potentiated the influx of macrophages and CD4+ T-lymphocytes whereas propranolol tended to reduce immune cell invasion. These data are hard to reconcile with many in vitro studies in which catecholamines acting mainly via β2-adrenoceptors have inhibited the activation and proliferation of immune cells following an inflamma- tory challenge.

Autonomic Neuroscience: Basic and Clinical 182 (2014) 108–117

Neuroscience Research Australia, Randwick, NSW 2031, and the University of New South Wales, Sydney, NSW 2052, Australia

The courts have become the sole policing body for the medical profession

Major lawsuits, with the major judgments that go with them, may not completely keep negligent physicians from practicing, but they are the one way that currently exists to deter these individuals from practicing their inept brand of medicine. "

Over the years, we have given a lot of thought to why the medical profession adheres to this code of silence. What is it about this profession that causes it to protect its own at the expense of the public?"

Harvey F. Wachsman: Lethal Medicine

Publisher: Henry Holt & Co

why doctors did not react as individuals to such an incomprehensible assertion

“I cannot help but wonder how such a situation came to develop… If I had been told by a physician, no matter how senior, that infants don’t feel pain, I would never have believed it. What constitutes the difference between my reaction and that of the thousands of physicians who did believe it?” Jill Lawson, 1988

In a letter published in the New England Journal of Medicine she questioned why doctors did not react as individuals to such an incomprehensible assertion.

The reasons why doctors traditionally take so long to question dogma are complex but we are known to be a rather conservative group of people. As late as 1974, experiments were still being conducted to ascertain whether infants felt pain.

http://www.mjainsight.com..._id=8674&cat=comment

our ignorance of the mechanisms for primary hyperhidrosis and of the effect of sympathetic ablation

Cell body reorganization in the spinal cord after elective surgery to treat sweaty palms

The amount of compensatory sweating depends on the patient, the damage that the white rami communicans incurs, and the amount of cell body reorganization in the spinal cord after surgery.
Other potential complications include inadequate resection of the ganglia, gustatory sweating, pneumothorax, cardiac dysfunction, post-operative pain, and finally Horner’s syndrome secondary to resection of the stellate ganglion.
www.ubcmj.com/pdf/ubcmj_2_1_2010_24-29.pdf

After severing the cervical sympathetic trunk, the cells of the cervical sympathetic ganglion undergo transneuronic degeneration
After severing the sympathetic trunk, the cells of its origin undergo complete disintegration within a year.
http://www.date.hu/acta-agraria/2002-08i/welento.pdf

cross-inhibitory control of various afferent in the spinal cord

In conclusion, our results suggest that cross-inhibitory control by various afferents in the spinal cord may exist in the feet as well as in the contralateral hand. The release of cross-inhibitory control by T3 sympathicotomy results in vasoconstriction and a decrease of skin temperature on the contralateral hand and the feet.

The basic neuronal network for this reciprocal organization is probably located in the spinal level (15). Therefore, the reduction in the contralateral skin temperature may be explained by cross-inhibitory control of various afferent in the spinal cord.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2722005/

Contralateral temperature changes of the finger surface during video endoscopic sympathectomy for palmar hyperhidrosis
http://www.ncbi.nlm.nih.gov/pubmed/8832515