Activity-dependent variations in conduction velocity of C fibers of rat sciatic nerve

We evaluated the repair of seccioned rat sciatic nerve by the comparison of electrophysiologic parameters. The repair was effected with suture (group A), fibrin glue (group B) or a combination of both techniques (group C). The amplitude, latency and conduction velocity of the motor and nerve action potentials were assessed before the nerve section and at reoperation after 24 weeks. There was no difference between the groups when the nerve action potential was evaluated. Rats of group B presented better results than those of group A (p<0.05) when latency and the nerve conduction velocity assessed at the reoperation, and the ratio between the conduction velocity at the reoperation and before the nerve section in the motor action potential evaluation were measured. Animals of group C presented better results than those of group A when the ratio between the conduction velocity of motor action potential at the reoperation and before the nerve division was considered (p<0.05). No difference between groups B and C was found. We conclude that repair using fibrin glue presented better results than suture following transection of sciatic nerve when the motor action potential was evaluated in the rat experimental model.

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The Effect of Tramadol on the Rat Sciatic Nerve Conduction: A Numerical Analysis and Conduction Velocity Distribution Study

YAKUGAKU ZASSHI ◽

10.1248/yakushi.129.485 ◽

2009 ◽

Vol 129 (4) ◽

pp. 485-493 ◽

Cited By ~ 14

Author(s):

Nizamettin DALKILIC ◽

Seckin TUNCER ◽

Hulagu BARISKANER ◽

Erhan KIZILTAN

Keyword(s):

Numerical Analysis ◽

Sciatic Nerve ◽

Velocity Distribution ◽

Conduction Velocity ◽

Nerve Conduction ◽

Distribution Study ◽

Rat Sciatic Nerve ◽

Conduction Velocity Distribution

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Capsaicin Combined with Local Anesthetics Preferentially Prolongs Sensory/Nociceptive Block in Rat Sciatic Nerve

Anesthesiology ◽

10.1097/aln.0b013e31818958f7 ◽

2008 ◽

Vol 109 (5) ◽

pp. 872-878 ◽

Cited By ~ 41

Author(s):

Peter Gerner ◽

Alexander M. Binshtok ◽

Chi-Fei Wang ◽

Nathanael D. Hevelone ◽

Bruce P. Bean ◽

...

Keyword(s):

Sciatic Nerve ◽

Quaternary Ammonium ◽

Local Anesthetics ◽

Transient Receptor Potential ◽

Receptor Potential ◽

Transient Receptor Potential Vanilloid ◽

Simultaneous Application ◽

Rat Sciatic Nerve ◽

C Fibers ◽

Transient Receptor

Background Transient receptor potential vanilloid 1 channels integrate nociceptive stimuli and are predominantly expressed by unmyelinated C-fiber nociceptors, but not low-threshold mechanoreceptive sensory or motor fibers. A recent report showed that the transient receptor potential vanilloid 1 channel agonist capsaicin allows a hydrophilic quaternary ammonium derivative of lidocaine, QX-314, to selectively block C fibers without motor block. The authors tested whether a similar differential block would be produced using amphipathic N-methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, either alone or together with 0.05% capsaicin, in a rat sciatic nerve block model. Methods Rats (n = 8/group) were anesthetized with sevoflurane, and 0.2 ml of drug was injected either alone or with capsaicin (simultaneously or 10 min later) next to the sciatic nerve in the sciatic notch. Motor function was assessed by the extensor postural thrust. Nociception was evaluated by the nocifensive withdrawal reflex and vocalization evoked by pinch of a skin fold over the lateral metatarsus (cutaneous pain) with a serrated forceps. Results N-Methyl amitriptyline, amitriptyline, bupivacaine, or lidocaine, followed by injection of capsaicin 10 min later, each elicited a predominantly nociceptive-specific blockade. In comparison, simultaneous application of each local anesthetic with capsaicin did not elicit a clinically significant differential block, with the exception of N-methyl amitriptyline. Conclusions Both tertiary amine local anesthetics and their quaternary ammonium derivatives can elicit a predominantly sensory/nociceptor selective block when followed by injection of capsaicin. The combined application of transient receptor potential vanilloid 1 channel agonists and various local anesthetics or their quaternary ammonium derivatives is an appealing strategy to achieve a long-lasting differential block in regional analgesia.

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Effect of diabetes on motor conduction velocity in different branches of the rat sciatic nerve

Experimental Neurology ◽

10.1016/0014-4886(86)90315-8 ◽

1986 ◽

Vol 92 (3) ◽

pp. 757-761 ◽

Cited By ~ 14

Author(s):

Norman E. Cameron ◽

Mary A. Cotter ◽

Jacqueline Harrison

Keyword(s):

Sciatic Nerve ◽

Conduction Velocity ◽

Motor Conduction Velocity ◽

Rat Sciatic Nerve

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Preferential Block of Small Myelinated Sensory and Motor Fibers by Lidocaine

Anesthesiology ◽

10.1097/00000542-200112000-00025 ◽

2001 ◽

Vol 95 (6) ◽

pp. 1441-1454 ◽

Cited By ~ 71

Author(s):

Alexander P. Gokin ◽

Benjamin Philip ◽

Gary R. Strichartz

Keyword(s):

Sciatic Nerve ◽

Conduction Velocity ◽

Differential Susceptibility ◽

Nerve Fibers ◽

Motor Deficits ◽

Sprague Dawley ◽

Size Principle ◽

Functional Deficits ◽

Myelinated Fibers ◽

C Fibers

Background Controversy still surrounds the differential susceptibility of nerve fibers to local anesthetics and its relation to selective functional deficits. In the current study we report features of conduction blockade in different classes of rat sciatic nerve fibers after injection of lidocaine by a percutaneous procedure that closely resembles clinical applications. Methods In 30 adult male Sprague-Dawley rats (weight, 300-400 g) during general anesthesia, impulses were recorded in different classes of sensory axons (large, Aalpha and beta fibers; small, Adelta myelinated fibers and unmyelinated C fibers) and motor axons (large, Aalpha fibers; small, Agamma myelinated fibers) classified by conduction velocity. The sciatic nerve was stimulated distally, and impulses were recorded from small filaments teased from L4-L5 dorsal (sensory) and ventral (motor) roots sectioned acutely from the spinal cord. Lidocaine at concentration of 0.05-1% was injected percutaneously in 0.1-ml solutions at the sciatic notch. Both tonic (stimulated at 0.5 Hz) and use-dependent (stimulated at 40 Hz for Adelta and Agamma fibers and at 5 Hz for C fibers) impulse inhibitions by lidocaine were assayed. Results Minimal effective (threshold) lidocaine concentrations (i.e., to block conduction in 10% of fibers) were, for sensory, 0.03% for Adelta, 0.07% for Aalphabeta, and 0.09-0.1% for C fibers, and for motor, 0.03% for Agamma and 0.05% for Aalpha fibers. The order of fiber susceptibility, ranked by concentrations that gave peak tonic fiber blockade of 50% (IC50s), was Agamma > Adelta = Aalpha > Aalphabeta > C. Faster-conducting C fibers (conduction velocity > 1 m/s) were more susceptible (IC50 = 0.13%) than slower ones (conduction velocity < 1 m/s; IC50 = 0.30%). At 1% lidocaine, all fibers were tonically blocked. Use-dependent effects accounted for only a modest potentiation of block (at a lidocaine concentration of 0.25%) in Adelta and Agamma fibers, and in C fibers phasic stimulation had even smaller effects and sometimes relieved tonic block. Conclusions Susceptibility to lidocaine does not strictly follow the "size principle" that smaller (slower) axons are always blocked first. This order of fiber blockade is qualitatively consistent with previous reports of the order of functional deficits in the rat after percutaneous lidocaine, that is, motor = proprioception > nociception, if we assume that motor deficits first arise from conduction failure in Agamma fibers and that nociception relies on C fiber conduction.

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Effects of Ozone on Sciatic Nerve in Rat

Interventional Neuroradiology ◽

10.1177/159101991101700301 ◽

2011 ◽

Vol 17 (3) ◽

pp. 281-285 ◽

Cited By ~ 5

Author(s):

Q. Lin ◽

H. Chen ◽

C. Lu ◽

B. Wang ◽

Y. Zhang ◽

...

Keyword(s):

Sciatic Nerve ◽

Peripheral Nerve ◽

Conduction Velocity ◽

Nerve Conduction ◽

Nerve Conduction Velocity ◽

Maximum Amplitude ◽

Structure And Function ◽

Group V ◽

Rat Sciatic Nerve ◽

And Function

This study evaluated the influence of ozone on rat sciatic nerve structure and function. Thirty Wistar rats were randomly divided into six groups (n = 5). In groups I to IV, 1ml of ozone (O3) 10 μg/ml, 30 μg/ml, 50 μg/ml, 80μg/ml was injected at the junction of gluteus maximus margin and lateral edge of the long head of biceps femoris respectively, in group V, 1 ml of pure O2 was injected at the same point, and group V had puncture without any injection. Ozone was manufactured by an ozone generator (Ozone Line Co, Italy). The rats were investigated by both gross measurement and behavioral changes. One day, one week and three weeks after injection, rat hindlimb footprints were measured and the sciatic nerve function index (SFI) was calculated, and after three weeks, all right sciatic nerves were exposed under anesthesia. Near neural stimulation of the rat sciatic nerve was calculated and nerve conduction velocity, latency and maximum amplitude recorded. Animals were sacrificed for pathology, and ipsilateral triceps surae were taken for wet weight. No serious behavioral abnormalities were observed in any animal. SFI comparison in the various times and various groups showed no significant differences (p<0.05), and nerve conduction velocity, latency and maximum amplitude difference amongst the groups was not significant (p<0.05). There were no abnormalities in peripheral nerves pathologically after injection. Our initial study suggests that ozone concentrations from 10 μg/ml to 80 μg/ml injected around rat's peripheral nerve will not cause serious sequelae or serious damage to the structure and function of peripheral nerve. This finding provides evidence of the safety of ozone injected around the peripheral nerve.

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