This experimental study was designed to unravel the relationship between muscle tension and its electrophysiological property. The experiments on repetitive pulse stimulus in different current intensity to rabbit's motor nerve were performed in different pulse frequency by electromyography which applied electrical pulses and excited the tibial nerve, and by Instron 5544 machine which measured muscle tensions. The experimental data revealed that the tension force varied with the stimulus frequency in a quasi-parabolic relation, while it seemingly increased little with the stimulus intensity.
Animals ; Electric Stimulation ; methods ; Electromyography ; Muscle Tonus ; physiology ; Muscle, Skeletal ; physiology ; Rabbits ; Tibial Nerve ; physiology

The aim of the present study was to establish a minimally invasive H reflex model in mice for the benefit of the research of clinical spinal cord injury and related diseases. Minimally invasive surgery was performed in hind limb of Kunming mouse under light anesthesia. The skin was incised at the point of one-third of the distance from greater trochanter to the base of the cauda. A pair of fine copper conductors were inserted into the shallow muscle using a syringe needle. After the needles were withdrawed, the retained conductors were ligated and fixed with the tissues surrounding the sciatic nerve as the first pair of stimulating electrodes. Another pair of conductors were inserted and fixed in medial malleolus close to the tibial nerve as the second stimulating electrodes. Copper conductor was inserted passing the skin above the proximal end of the metatarsal and fixed as the recording electrode. The reference electrode was placed at the walking pad in the base of the big toe using the same method. Electromyography (EMG) was used to record M and H waves in planta pedis muscles. The stimulus was a square wave with a width of 0.2 ms and frequency of 0.3 Hz. The latency time of the M and H waves which were induced from the two pairs of stimulating electrodes was recorded. Nerve conduction velocity (NCV) was then calculated from the distance between the cathodes of the stimulating electrodes and the latency time difference of M or H waves. The result showed the achievement ratios of H reflex induction were 92.73% and 81.82% in sciatic and tibial nerves, respectively. The latency time of H wave was about 7~10 ms. Motor nerve conduction velocity (MNCV) obtained was (25.84 ± 4.70) m/s (n = 35), while sensory nerve conduction velocity (SNCV) was (31.45 ± 7.30) m/s (n = 35). The method established in the present paper is simple to practice, does slight harm to the animal, and can produce waveforms with little interference. With these advantages, the method can be applied for the study of the latency of H reflex, and it is suitable for the researches which demands good physical condition of experimental animal during H reflex study. This model can also be applied to the detection of SNCV and MNCV.
Animals ; Electromyography ; H-Reflex ; physiology ; Hindlimb ; innervation ; Mice ; Neural Conduction ; physiology ; Tibial Nerve ; physiology

The somatosensory evoked potentials (SEPs), following stimulation of both the posterior tibial nerve (PTSEP) and pudendal nerve (PNSEP), comprise of the lumbar negative, subcortical and cortical potential. These can be used to assess the long somatosensory pathway, including peripheral, intraspinal and intracranial conduction along the entire length. This study aimed to compare the central conduction time between the PTSEP and the PNSEP, and to investigate the relationship between the intraspinal and intracranial conduction time in the SEP pathway. The SEPs following stimulation of the posterior tibial nerve at the ankle and the pudendal nerve at the shaft of the penis were analyzed in 20 normal male subjects. The central conduction of the PNSEP was found to be slower than that of the PTSEP (p <0.05). This difference is due to a delay in conduction rather than that of intracranial conduction.
Adolescence ; Adult ; Evoked Potentials, Somatosensory* ; Human ; Male ; Middle Age ; Neural Conduction* ; Penis/innervation* ; Tibial Nerve/physiology* ; Time Factors

OBJECTIVETo study the changes of the muscle strength after the selective tibial neurotomy and the relationship between the changes and the quantities of neurotomy, and to discuss the clinical significances.

METHODSTwenty-four normal SD rats were divided into 4 groups with 6 in each. In group A, the left tibia nerve were cut off by 80%. 60% in group B, 40% in group C, 20% in group D, with the right as the control side. After 6 weeks measure the strength of the crural triceps and the weight of them.

RESULTSIn all the groups muscle weight and muscle strength decreased. 88.2% strength decreased on the average in group A, 54.2% in group B, 19.5% in group C, 4.7% in group D.

CONCLUSIONIt will not damage strength of the crural triceps to cut off below 40% tibial nerve in SD rats.

Animals ; Female ; Male ; Muscle Contraction ; physiology ; Muscle Denervation ; Muscle, Skeletal ; innervation ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Tibial Nerve ; surgery

OBJECTIVETo study the changes in the levels of authophagy-related proteins ATG4A and p-ATG4A in nervous tissue after treated with tri-ortho-cresyl phosphate and explore the possible pathogenesis of OPIDN.

METHODSIn the first experiment, thirty hens were randomly divided into control group and 1 d, 5 d, 10 d and 21d treated groups, hens in treated groups were treated with TOCP by gavage at a single dosage of 600 mg/kg. In the second experiment, other thirty hens were also randomly divided into control group and 1 d, 5 d, 10 d and 21 d treated groups, hens in treated group were pretreated with PMSF by subcutaneous at a single dosage of 90 mg/kg. 24 h later, hens in intervention group was treated with TOCP by gavage at a single dosage of 600 mg/kg. The hens were killed at the corresponding time points, and collected their tibial nerves. The levels of ATG4A and p-ATG4A were measured by immunoblotting.

RESULTScompared with the control group, the levels of ATG4A decreased by36%, 43.7% and 41% at 1d, 5d and 10d in the intoxication groups (P < 0.05), the levels of p-ATG4A decreased by 22.5%, 25%and 21%at 1d, 5d and 10d in the intoxication group (P < 0.05). However, compared with the control group, there is no significant change in the levels of ATG4A and p-ATG4A in PMSF-pretreated groups.

CONCLUSIONThe intoxication of TOCP influence the levels of autophagy-related proteins ATG4A and p-ATG4A, which might be associated with the inhibition of autophagy activity in neurons of OPIDN.

Animals ; Apoptosis Regulatory Proteins ; metabolism ; Autophagy ; drug effects ; Chickens ; Female ; Nerve Tissue ; physiology ; Phosphorylation ; drug effects ; Tibial Nerve ; Tritolyl Phosphates ; toxicity

OBJECTIVE: To evaluate the diagnostic value of somatosensory evoked potential(SEP) in lumbosacral disc herniation(LDH). METHODS: Posterior tibial nerve somatosensory evoked potential(PTNSEP) and dermatomal somatosensory evoked potential (DSEP) were recorded from 60 patients with radiculopathy caused by LDH and 30 healthy subjects. RESULTS: DSEP was abnormal in 56 cases (93.3%) and PTNSEP was abnormal in 26 cases (43.3%). The significant difference was observed (P<0.001). The abnormality of DSEP from L4 dermatome was detected mainly in patients with L3-4 LDH, the abnormality of DSEP from L5 dermatome was detected mainly in patients with L4-5 LDH, the abnormality of DSEP from L5S1 dermatome was detected mainly in patients with S1 LDH. DSEP can reflect the compressed extent of nerve root. CONCLUSIONS There was a good correlation of DSEP with lumbosacral nerve root injury,which supplement the information that can not be provided by imaging examingation. DSEP is a sensitive electrophysic method that not only is used to evaluate single nerve root function, but also is helpful in the location of the lesion.
Adult ; Electric Stimulation ; Electrodiagnosis/methods* ; Evoked Potentials, Somatosensory ; Female ; Forensic Medicine ; Humans ; Intervertebral Disc Displacement/physiopathology* ; Lumbar Vertebrae ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Sensitivity and Specificity ; Spinal Nerve Roots/physiopathology* ; Tibial Nerve/physiology*