The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P < 0.01). TSR reached its peak on the 4th day in the group D and on the 10th day in the group E respectively. The amplitude and velocity of MCAP and NCAP in the group D was greater than in the group E with the difference being statistically significant (P < 0.01), while the latency and duration of MCAP and NCAP in the group D were less than in the group E with the difference being also statistically significant (P < 0.01). Histological examination showed the mean axon count above the lesion for thick myelinated fibers (> 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P < 0.01), while the mean axon count below the lesion for thick myelinated fibers was less than that in the group E with the difference being statistically significant (P < 0.01). The mean axon count above the lesion for thin myelinated fibers (2-6.5 microns) in the group D was greater than that in the group E with the difference being statistically significant (P < 0.05), while the mean axon count below the lesion for thin myelinated in the group D was greater than that in the group E with the difference being statistically significant (P < 0.01). Acetylcholine esterase examination showed that the MS could significantly increase the number of the motor neurons. There was no significant difference in the number of the motor neurons between the treatment side and the normal side (P > 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.
Acetylcholinesterase/metabolism ; Electromagnetics ; Motor Neurons/physiology ; *Nerve Regeneration ; Random Allocation ; Rats, Sprague-Dawley ; Sciatic Nerve/*injuries ; Sciatic Nerve/*physiopathology ; Sciatic Neuropathy/rehabilitation

There is close relationship between the morphologic changes of peripheral nerve after injury and its function recovery during regeneration. In our experiment, the sciatic nerve of rats was transected and bridge-connected with silicone tube, and the images of serial slices of different time and different injury parts were taken by micro-photograph system. The volume unit model was applied to rendering the three dimensional (3D) structure of degenerative and regenerative sciatic nerve fiber and its affiliated structure after injury. The 3D images showed that node of Ranvier had not formed and its array was turbulent, both the myelin sheath and the axis-cylinder were thinner, and the collagen fibres had proliferated.
Animals ; Male ; Nerve Regeneration ; physiology ; Rats ; Rats, Wistar ; Recovery of Function ; Sciatic Nerve ; injuries ; pathology ; physiopathology

The effect of magnetic stimulation (MS) on sciatic nerve injury was observed. After sciatic nerve was crushed in 40 Sprague Dawley (SD) rats, one randomly selected group (group D) was subjected, from the 4th day post-operatively to 3 min of continuous 70% of maximum output of MS daily for 8 weeks. The other group (group E) served as a control group. The nerve regeneration and motor function recovery were evaluated by walking track analysis (sciatic function index, SFI; toe spreading reflex, TSR), electrophysiological, histological and acetylcholineesterase histochemistry. The SFI in the group D was greater than in the group E with the difference being statistically significant (P < 0.01). TSR reached its peak on the 4th day in the group D and on the 10th day in the group E respectively. The amplitude and velocity of MCAP and NCAP in the group D was greater than in the group E with the difference being statistically significant (P < 0.01), while the latency and duration of MCAP and NCAP in the group D were less than in the group E with the difference being also statistically significant (P < 0.01). Histological examination showed the mean axon count above the lesion for thick myelinated fibers (> 6.5 microns) in the group D was greater than in the control group with the difference being statistically significant (P < 0.01), while the mean axon count below the lesion for thick myelinated fibers was less than that in the group E with the difference being statistically significant (P < 0.01). The mean axon count above the lesion for thin myelinated fibers (2-6.5 microns) in the group D was greater than that in the group E with the difference being statistically significant (P < 0.05), while the mean axon count below the lesion for thin myelinated in the group D was greater than that in the group E with the difference being statistically significant (P < 0.01). Acetylcholine esterase examination showed that the MS could significantly increase the number of the motor neurons. There was no significant difference in the number of the motor neurons between the treatment side and the normal side (P > 0.05). It can be concluded that MS can enhance functional recovery and has a considerable effect in the treatment of the peripheral nerve injury.
Acetylcholinesterase ; metabolism ; Animals ; Electromagnetic Phenomena ; Motor Neurons ; physiology ; Nerve Regeneration ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Sciatic Nerve ; injuries ; physiopathology ; Sciatic Neuropathy ; rehabilitation

OBJECTIVETo study the changes in sciatic nerve blood flow and the expression of collagen type I after electric injury of rabbit nerve with different voltages.

METHODSThirty-six healty rabbits were randomized into 3 groups before receiving injury with electricity in voltages, i.e. 50 v, 75 v, and 100 v groups. The changes in blood flow of sciatic nerve were observed with Laser Doppler Flowmeter immediately after injury and 1, 4, 8 weeks after injury. The changes in the expression of collagen type I was observed by immunohistochemical method, and the positive expression rate was calculated.

RESULTSThe sciatic nerve blood flow increased in all groups immediately after electric injury. In the 75 v and 100v groups, the nerve blood flow [(53 +/- 3 ), (48 +/- 5) PU] was obviously lower than that of normal value [(62 +/- 4) PU, P < 0.05]. There was little collagen type I deposition in 50 v group, while brown collagenous fibers in epineurium and perineurium were observed in 75 v and 100v groups 4 and 8 weeks after injury. The expression of collagen type I in all groups were obviously higher than that of normal value, and that in 75v and 100 v groups were higher than that in 50 v group at bachl time-point (P < 0.01).

CONCLUSIONThe restoration of sciatic nerve blood flow is postponed following by the injury with increase of the electrical voltage. The collagen deposition after electrical injury may be one of the reasons for nerve blood flow decrease.

Animals ; Collagen Type I ; biosynthesis ; Electric Injuries ; blood ; physiopathology ; Nerve Regeneration ; Rabbits ; Random Allocation ; Sciatic Nerve ; blood supply ; injuries

OBJECTIVETo probe into the mechanism of electroacupuncture at shu-points of the five zang-organs for treatment of Guillain-Barre syndrome (GBS).

METHODSEighty healthy giant-ear white rabbits were randomly divided into 4 groups, a blank group, a model group, an electroacupuncture (EA) group and an immunoglobulin group, 20 rabbits in each group. The internationally recognized P 2 immune rabbit model was used in the study. The EA group were treated with EA at shu-points of the five zang-organs and the immunoglobulin group with intravenous injection of immunoglobulin 80 mg/kg/day. The sciatic nerve movement conduction velocity (MCV) and F wave incidence rate were investigated respectively at the 7th and 14th days of treatment in the rabbits of GBS.

RESULTSThe sciatic nerve MCV significantly reduced in the model group, and it significantly increased (P < 0.01) and F wave abnormal cases was significantly reduced (P < 0.05) after treatment for 14 days in the EA group as compared with those in the model group.

CONCLUSIONEA at shu-points of the five zang-organs can increase the sciatic nerve MCV and decrease the abnormal F wave incidence rate of the sciatic nerve in the rabbit of GBS.

Acupuncture Points ; Animals ; Electroacupuncture ; Female ; Guillain-Barre Syndrome ; physiopathology ; therapy ; Male ; Neural Conduction ; Rabbits ; Sciatic Nerve ; physiopathology

Cadaver ; Humans ; India ; Models, Anatomic ; Models, Neurological ; Peroneal Nerve ; anatomy & histology ; Piriformis Muscle Syndrome ; physiopathology ; Sciatic Nerve ; anatomy & histology ; physiopathology ; Sciatica ; pathology ; Tibia ; innervation ; pathology

OBJECTIVETo investigate the effect of 2,5-hexanedione (HD) on degradation of low-molecular-weight neurofilaments (NF-L) in nervous tissue of rats, and to explore the molecular mechanism of n-hexane neuropathy.

METHODSFifty male Wistar rats were randomly divided into one-week poisoning group (n = 10), two-week poisoning group (n = 10), three-week poisoning group (n = 10), four-week poisoning group (n = 10), and control group (n = 10). In the four poisoning groups, a rat model of n-hexane neuropathy was established by intraperitoneal injection of HD (400 mg/kg/d). The change in the sciatic nerve ultrastructure of each rat was observed under an electron microscope. The progression of HD-induced peripheral neuropathy was evaluated using a gait scoring system. The degradation rates of NF-L in the sciatic nerve and spinal cord of each rat were measured by Western Blotting.

RESULTSThe rats showed decrease in muscle strength and abnormal gait after two weeks of HD poisoning and mild or moderate paralysis after four weeks of HD poisoning. The sciatic nerve showed degenerative change, according to electron microscope observation. Compared with the control group, the two-week poisoning group, three-week poisoning group, and four-week poisoning group had the NF-L degradation rates decreased by 25.8%, 70.4%, and 69.7%, respectively, in the supernatant fraction of sciatic nerve, and by 14.7%, 64.6%, and 67.3%, respectively, in the sediment fraction of sciatic nerve, all showing a significant difference (P < 0.01). Compared with the control group, the one-week poisoning group had the NF-L degradation rate decreased by 33.87% in the supernatant fraction of spinal cord, the four-week poisoning group had the NF-L degradation rate increased by 16.2% in the supernatant fraction of spinal cord, and the one-week poisoning group and two-week poisoning group had the NF-L degradation rates decreased by 46.3% and 13.0% in the sediment fraction of spinal cord, all showing a significant difference (P < 0.01).

CONCLUSIONHD poisoning significantly inhibits NF-L degradation in the sciatic nerve, which may be associated with NF degeneration and accumulation in the axons of patients with n-hexane neuropathy.

Animals ; Hexanes ; poisoning ; Hexanones ; pharmacology ; Male ; Nerve Tissue ; drug effects ; metabolism ; physiopathology ; Neurofilament Proteins ; drug effects ; metabolism ; Rats ; Rats, Wistar ; Sciatic Nerve ; drug effects ; metabolism ; physiopathology

Bone marrow mesenchymal stem cells (BMSCs) possess the potential of self-duplication, multi-directional differentiation, and also the ability to differentiate (in the direction of ectoderm) into neuron and neuroglial cells in vitro as well as to promote the reparation of sciatic nerve injury in vivo, especially for the reparation of the long-segment nerve. Progress in repair of sciatic nerve injury by BMSCs has been reviewed in this article.
Bone Marrow Cells ; cytology ; physiology ; Humans ; Mesenchymal Stromal Cells ; cytology ; physiology ; Nerve Regeneration ; physiology ; Peripheral Nerve Injuries ; physiopathology ; therapy ; Sciatic Nerve ; injuries ; physiology ; Stem Cell Transplantation ; methods

Sciatic nerve injury is a common disease of peripheral nerve in clinic. After nerve injury, there are many dysfunctions in motoneurons and muscles following regeneration. Previous studies mostly investigated the aspects related to the injured nerve, and the effect on the recurrent inhibition (RI) pathway of spine following regeneration was not fully understood. Following reinnervation after temporary sciatic nerve crush, the functional alteration of RI was studied. In adult rats, RI between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSRs) elicited from the cut dorsal roots and recorded from either the LG-S or MG nerves by antidromic stimulation of the synergist muscle nerve. The following results were obtained. (1) The RI of MSRs in rats was almost lost (<5 weeks) after sciatic nerve crush. Although the RI partially recovered following reinnervation (6 weeks), it remained permanently depressed (up to 14 weeks). (2) Sciatic nerve crush on one side did not affect the contralateral RI. (3) Sciatic nerve crush did not induce any motoneuron loss revealed by immunohistochemistry. Peripheral nerve temporary disconnection causes long term alterations in RI pathway which make up motoneuron's function enhance for the alteration of muscle power and suggests that peripheral nerve injury induces long term plastic changes in the spinal motoneuron circuitry.
Animals ; Long-Term Synaptic Depression ; physiology ; Male ; Motor Neurons ; physiology ; Nerve Crush ; Nerve Regeneration ; physiology ; Neuronal Plasticity ; physiology ; Neurons, Afferent ; physiology ; Rats ; Rats, Wistar ; Reflex, Monosynaptic ; physiology ; Sciatic Nerve ; injuries ; physiopathology ; Spinal Cord ; physiopathology ; Spinal Nerve Roots ; physiopathology

BACKGROUNDPain physicians pay close attention to neuropathic pain (NP), since there is currently no ideal treatment. Radial shock wave therapy (RSWT) is a noninvasive treatment to chronic pain of soft tissue disorders. So far, there is no information on the use of RSWT for the treatment of NP. Therefore we observe the effects of RSWT on a NP model induced by chronic constriction injury (CCI) in rats.

METHODSFour different energy densities (1.0, 1.5, 2.0 and 2.5 bar) RSWT administered as a single session or repeated sessions in rats with NP induced by CCI of the sciatic nerve. The analgesic effect was assessed by measuring mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL). The safety was assessed through calculating sciatic functional index (SFI).

RESULTSMWT and TWL increased after a single session of RSWT from day 1 to day 5 but returned to baseline levels by day 10. Following repeated sessions of RSWT, both the MWT and TWL were significantly higher than NP group (P < 0.01) for at least 4 weeks. In addition, no significant changes of SFI were observed in any groups after repeated sessions of RSWT and no increased pain or other side effects in any animals.

CONCLUSIONSA single session of RSWT is rapidly effective in the treatment of CCI, but the efficacy maintained in a short period. However, repeated sessions of RSWT have prolonged efficacy.

Animals ; Chronic Pain ; therapy ; High-Energy Shock Waves ; Male ; Neuralgia ; therapy ; Rats, Sprague-Dawley ; Sciatic Nerve ; physiopathology