Investigation of Neuropathology after Nerve Release in Chronic Constriction Injury of Rat Sciatic Nerve

Peripheral compressive neuropathy causes significant neuropathic pain, muscle weakness and prolong neuroinflammation. Surgical decompression remains the gold standard of treatment but the outcome is suboptimal with a high recurrence rate. From mechanical compression to chemical propagation of the local inflammatory signals, little is known about the distinct neuropathologic patterns and the genetic signatures after nerve decompression. In this study, controllable mechanical constriction forces over rat sciatic nerve induces irreversible sensorimotor dysfunction with sustained local neuroinflammation, even 4 weeks after nerve release. Significant gene upregulations are found in the dorsal root ganglia, regarding inflammatory, proapoptotic and neuropathic pain signals. Genetic profiling of neuroinflammation at the local injured nerve reveals persistent upregulation of multiple genes involving oxysterol metabolism, neuronal apoptosis, and proliferation after nerve release. Further validation of the independent roles of each signal pathway will contribute to molecular therapies for compressive neuropathy in the future.

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Effects of 660- and 980-nm low-level laser therapy on neuropathic pain relief following chronic constriction injury in rat sciatic nerve

Lasers in Medical Science ◽

10.1007/s10103-014-1552-1 ◽

2014 ◽

Vol 29 (5) ◽

pp. 1593-1598 ◽

Cited By ~ 33

Author(s):

M. Masoumipoor ◽

S. B. Jameie ◽

A. Janzadeh ◽

F. Nasirinezhad ◽

M. Soleimani ◽

...

Keyword(s):

Neuropathic Pain ◽

Pain Relief ◽

Sciatic Nerve ◽

Laser Therapy ◽

Chronic Constriction Injury ◽

Low Level Laser Therapy ◽

Low Level ◽

Rat Sciatic Nerve ◽

Low Level Laser ◽

Level Laser

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Effects of 660 nm Low Level Laser Therapy on Neuropathic Pain Relief Following Chronic Constriction Injury in Rat Sciatic Nerve

Archives of Neuroscience ◽

10.5812/archneurosci.13740 ◽

2013 ◽

Vol 1 (2) ◽

pp. 76-81 ◽

Cited By ~ 3

Author(s):

Masoume Masoumipoor ◽

Seyed Behnam Jameie ◽

Atusa Janzadeh ◽

Farinaz Nasirinezhad ◽

Mahdie Kerdari ◽

...

Keyword(s):

Neuropathic Pain ◽

Pain Relief ◽

Sciatic Nerve ◽

Laser Therapy ◽

Chronic Constriction Injury ◽

Low Level Laser Therapy ◽

Low Level ◽

Rat Sciatic Nerve ◽

Low Level Laser ◽

Level Laser

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N -Phenylethyl Amitriptyline in Rat Sciatic Nerve Blockade

Anesthesiology ◽

10.1097/00000542-200206000-00024 ◽

2002 ◽

Vol 96 (6) ◽

pp. 1435-1442 ◽

Cited By ~ 22

Author(s):

Peter Gerner ◽

Mustafa Mujtaba ◽

Mohammed Khan ◽

Yukari Sudoh ◽

Kamen Vlassakov ◽

...

Keyword(s):

Neuropathic Pain ◽

Sciatic Nerve ◽

Therapeutic Range ◽

Local Anesthetic ◽

Na Channel ◽

Patch Clamp Technique ◽

Rat Sciatic Nerve ◽

Nerve Model

Background The antidepressant amitriptyline is commonly used orally for the treatment of chronic pain, particularly neuropathic pain, which is thought to be caused by high-frequency ectopic discharge. Among its many properties, amitriptyline is a potent Na(+) channel blocker in vitro, has local anesthetic properties in vivo, and confers additional blockade at high stimulus-discharge rates (use-dependent blockade). As with other drug modifications, adding a phenylethyl group to obtain a permanently charged quaternary ammonium derivative may improve these advantageous properties. Methods The electrophysiologic properties of N-phenylethyl amitriptyline were assessed in cultured neuronal GH(3) cells with the whole cell mode of the patch clamp technique, and the therapeutic range and toxicity were evaluated in the rat sciatic nerve model. Results In vitro, N-phenylethyl amitriptyline at 10 microm elicits a greater block of Na(+) channels than amitriptyline (resting block of approximately 90% vs. approximately 15%). This derivative also retains the attribute of amitriptyline in evoking high-degree use-dependent blockade during repetitive pulses. In vivo, duration to full recovery of nociception in the sciatic nerve model was 1,932 +/- 72 min for N-phenylethyl amitriptyline at 2.5 mm (n = 7) versus 72 +/- 3 min for lidocaine at 37 mm (n = 4; mean +/- SEM). However, there was evidence of neurotoxicity at 5 mm. Conclusion N-phenylethyl amitriptyline appears to have a narrow therapeutic range but is much more potent than lidocaine, providing a block duration several times longer than any clinically used local anesthetic. Further work in animal models of neuropathic pain will assess the potential use of this drug.

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