The capacity of embryonic spinal cord tissue in the repair of injured structure of spinal cord has been noted for years. In order to investigate the embryonic spinal cord graft in the repair of motor function of injured spinal cord, the embryonic spinal cord tissue was transplanted to the hemisection cavity in spinal cord in adult rat. One hundred adult Wistar Rats were used to simulate the hemisectional injury of spinal cord by drilling 2-3 mm cavity in lumbar enlargement. Sixty rats were treated with rat embryonic spinal cord tissue grafting while the other forty were chosen as control. The outcome was evaluated according the combined behavioural score (CBS) and motor evoked potential (MEP) in the 1, 2, 4 and 12 weeks. The grafting group was superior to the control as assessed by CBS (P lt; 0.05), especially within 4 weeks. (P lt; 0.01). The restoration of the latent peak of early wave(P1, N1) was better in the grafting group, too. This suggested that embryonic spinal cord graft could improve the recovery of motor function of injured spinal cord in adult rat. The effect of the embryonic spinal cord tissue graft might be concerned with its secretion of several kinds of neurotrophic factors, nerve growth factor, nerve transmitted factor, or adjustment of hormone.
Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive brain stimulation technique that has been paid attention to with increasing interests as a therapeutic neural rehabilitative tool. Studies confirmed that high-frequency rTMS could improve the cognitive performance in behavioral test as well as the excitability of the neuron in animals. This study aimes to investigate the effects of rTMS on the cognition and neuronal excitability of Kunming mice during the natural aging. Twelve young mice, 12 adult mice, and 12 aged mice were used, and each age group were randomly divided into rTMS group and control group. rTMS-treated groups were subjected to high-frequency rTMS treatment for 15 days, and control groups were treated with sham stimulation for 15 days. Then, novel object recognition and step-down tests were performed to examine cognition of learning and memory. Whole-cell patch clamp technique was used to record and analyze resting membrane potential, action potential (AP), and related electrical properties of AP of hippocampal dentate gyrus (DG) granule neurons. Data analysis showed that cognition of mice and neuronal excitability of DG granule neurons were degenerated significantly as the age increased. Cognitive damage and degeneration of some electrical properties were alleviated under the condition of high-frequency rTMS. It may be one of the mechanisms of rTMS to alleviate cognitive damage and improve cognitive ability by changing the electrophysiological properties of DG granule neurons and increasing neuronal excitability.
ObjectiveTo detect expressions of transient receptor potential channel C5 (TRPC5) and microRNA-320a (miR-320a) in thyroid cancer and explore clinical significances of them in thyroid cancer.MethodsThe expressions of TRPC5 and miR-320a mRNA in the thyroid cancer were investigated by searching the Ualcan database. While the expressions of TRPC5 and miR-320a mRNA in 80 cases of thyroid cancer, 35 cases of thyroid adenoma and 32 cases of normal thyroid tissues adjacent to thyroid adenoma tissues in the Zhengzhou Seventh People’s Hospital from March 2014 to March 2015 were tested. Real time PCR was used to detect the expressions of TRPC5 mRNA and miR-320a mRNA in the various tissues and Western blot was used to detect the TRPC5 protein in the thyroid cancer tissues. Therelationships between the expressions of TRPC5 and miR-320a mRNAs and clinicopathologic features of thyroid cancer were analyzed. The correlation between expressions of TRPC5 and miR-320a mRNA was analyzed by Pearson method. The risk factors influencing the prognosis were analyzed by univariate and multivariate Cox proportional hazards regression model.ResultsThe results of Ualcan database showed that the expression level of TRPC5 mRNA in the thyroid cancer was higher than that in the normal thyroid tissue (P<0.001), while the expression level of miR-320a mRNA was lower than that in the normal thyroid tissue (P<0.001). The results of clinical cases showed that the expression level of TRPC5 mRNA was significantly higher, while the expression of miR-320a mRNA was significantly lower in the thyroid cancer tissues as compared with the normal thyroid tissues (P<0.05). There was a negative correlation between the expression level of TRPC5 and miR-320a mRNA in the thyroid cancer (r=−0.653, P<0.001). The expressions of TRPC5 and miR-320a mRNA were correlated with the degree of differentiation, lymph node metastasis, and TNM stage (P<0.05). Kaplan-Meier survival curve analysis found that the patients with higher expression level of TRPC5 and lower expression level of miR-320a showed the poor prognosis, and multivariate analysis found that the lower tumor differentiation, later TNM stage, with lymph node metastasis, higher expression level of TRPC5 mRNA, and lower expression level of miR-320a mRNA were the risk factors affecting prognostic survival (P<0.05).ConclusionsFrom the database and clinical case data, it is concluded that TRPC5 mRNA is highly expressed, while miR-320a mRNA is lowly expressed in thyroid cancer tissues, and expressions of TRPC5 and miR-320a mRNA are related to degree of tumor differentiation, lymph node metastasis, TNM staging, and prognosis in patients with thyroid cancer. TRPC5 and miR-320a mRNA might be used as potential indicators for clinical and prognostic monitoring.
As a noninvasive neuromodulation technique, transcranial magnetic stimulation (TMS) is widely used in the clinical treatment of neurological and psychiatric diseases, but the mechanism of its action is still unclear. The purpose of this paper is to investigate the effects of different frequencies of magnetic stimulation (MS) on neuronal excitability and voltage-gated potassium channels in the in vitro brain slices from the electrophysiological perspective of neurons. The experiment was divided into stimulus groups and control group, and acute isolated mice brain slices were applied to MS with the same intensity (0.3 T) at different frequencies (20 Hz and 0.5 Hz, 500 pulses) respectively in the stimulus groups. The whole-cell patch clamp technique was used to record the resting membrane potential (RMP), action potential (AP), voltage-gated potassium channels current of hippocampal dentate gyrus (DG) granule cells. The results showed that 20 Hz MS significantly increased the number of APs released and the maximum slope of a single AP, reduced the threshold of AP, half width and time to AP peak amplitude, and improved the excitability of hippocampal neurons. The peak currents of potassium channels were decreased, the inactivation curve of transient outward potassium channels shifted to the left significantly, and the time constant of recovery after inactivation increased significantly. 0.5 Hz MS significantly inhibited neuronal excitability and increased the peak currents of potassium channels, but the dynamic characteristics of potassium channels had little change. The results suggest that the dynamic characteristics of voltage-gated potassium channels and the excitability of hippocampal DG granule neurons may be one of the potential mechanisms of neuromodulation by MS.
Objective To investigate the distribution properties of multifocal pattern visual evoked potential across visual field. Methods Multifocal pattern visual evoked potentials(VEP) of 14 normals were measured with VERIS ScienceTM4.0The visual stimuli were dart board 60 with patterns which consisted of 60 patches arranged in dart board configuration spanning a 26deg; vis ual field. The temporal modulation of each patch was controlled by a special type of pseudorandom sequence called binary m-sequence. The electrodes were placed at equal distances 2 cm inferior to and 2 cm superior to and straddling the inion. The first slice of the second order kernel for each stimulus patch was analysed. The 60 patches were grouped into several sectors. The summed responses of these sectors were analysed and compared. Results Compared with that of the lower hemifield , the polarity of the multifocal VEP of the upper hemifield was reverse, and the latency delayed, the response density decreased. With the eccentricity increased, the response density of the multifocal VEP decreased. The properties of the multifocal VEP of the horizontal sectors were different from that of the vertical sectors. Conclusion VEP of many locations within visual field could be recorded simultaneously in a short time with the method of mutifocal VEP. The multifocal VEP showed different properties in different sectors within visual field. (Chin J Ocul Fundus Dis, 2001,17:280-283)
Electric field stimulation (EFS) can effectively inhibit local Ca2+ influx and secondary injury after spinal cord injury (SCI). However, after the EFS, the Ca2+ in the injured spinal cord restarts and subsequent biochemical reactions are stimulated, which affect the long-term effect of EFS. Polyethylene glycol (PEG) is a hydrophilic polymer material that can promote cell membrane fusion and repair damaged cell membranes. This article aims to study the combined effects of EFS and PEG on the treatment of SCI. Sprague-Dawley (SD) rats were subjected to SCI and then divided into control group (no treatment, n = 10), EFS group (EFS for 30 min, n = 10), PEG group (covered with 50% PEG gelatin sponge for 5 min, n = 10) and combination group (combined treatment of EFS and PEG, n = 10). The measurement of motor evoked potential (MEP), the motor behavior score and spinal cord section fast blue staining were performed at different times after SCI. Eight weeks after the operation, the results showed that the latency difference of MEP, the amplitude difference of MEP and the ratio of cavity area of spinal cords in the combination group were significantly lower than those of the control group, EFS group and PEG group. The motor function score and the ratio of residual nerve tissue area in the spinal cords of the combination group were significantly higher than those in the control group, EFS group and PEG group. The results suggest that the combined treatment can reduce the pathological damage and promote the recovery of motor function in rats after SCI, and the therapeutic effects are significantly better than those of EFS and PEG alone.
Objective To compare the effect of electrode positions on multifocal visual evoked potential(mf-VEP). Methods Ten healthy individuals were tested with RETIscan multifocal VEP system 3.20, each individual was tested with four electrode positions: the active and reference electrode were placed 2.0 cm above and below the inion in Ch1；3.0 cm above and 4.5 cm below the inion in Ch2；2.0 cm on both right and left side of the inion in Ch3 and 4.0 cm on both right and left side of the inion in Ch4. The summed amplitudes of hemifield mf-VEP were analyzed and compared according to different electrode positions. Results The difference among summed amplitudes of the upper or lower hemifield mf-VEP recorded with Ch1、Ch2、Ch3 and Ch4 was statistically significant；and the difference between Ch2 and the other channels was statistically significant too. The difference among summed amplitudes of the horizontal sites whose amplitudes were small when recorded with Ch2 and summed amplitudes of the corresponding sites recorded with Ch3 and Ch4 were statistically significant；and the difference between Ch4 and the other channels was statistically significant too. Conclusions compared to Ch1、Ch3 and Ch4, Ch2 can make a better recording of mf-VEP. As for some sites, especially those along horizontal line, horizontal electrodes could improve the amplitudes of mf-VEP recorded with vertical electrodes，and Ch4 could do better to improve the mf-VEP recorded with Ch2 than Ch3. (Chin J Ocul Fundus Dis，2004，20：346-348)
A new form of static random-dot stereograms free of monocular clues was designed as stimulus to elicit disparity evoked potentials in 40 normal subjects.A characteristic wide positive wave at about 250ms was consistently recorded in disparity stimulation,which may be regard as evdence of the presence of stereopsis.In constrast,recordings for monocular stimulus all demonstrated a relatively smaller and sharper positive wave with a markedly shortened latency. （Chin J Ocul Fundus Dis,1993,9:214-217）
Purpose To investigate the influence of ametropia on stereopsis and its mechanism by using the disparity evoked potential testing. Methods A new set of static random dot stereograms was utilized as a stimulation to elicit the disparity evoked potentials in 21 ametropes and 40 stereo normal subjects. Rezults The P250 wave,which was related to stereoscopic stimulation in ametropes,was recorded in both the ametropes and emetropic stereo normal persons in this series,and the characteristic changes of P250 wave with increasing visual disparity in ametropes were similar to those in normal subjects.The differences of mean amplitudes and latencies of P250 waves between myopes and hyperopes were not significant. Conclusion Ametropia in full correction dose not significanly affect the function of stereopsis. (Chin J Ocul Fundus Dis,1998,14:225-227)
ObjectiveTo evaluate the differences of visual evoked potentials (amplitudes and latency) between cerebral palsy (CP) children and normal children. MethodsThis study involved fourteen children aged from 4 to 7 years with CP (monoplegia) between 2009 and 2013. Another 14 normal children aged from 5 to 9 years treated in the Department of Ophthalmology in West China Hospital during the same period were regarded as the control group. Both eyes of all the participants were examined by multifocal visual evoked potential (mfVEP). The mfVEP examination results were recorded, and amplitude and latency were analyzed. First, we analyzed the differences of amplitudes and latency time between monoplegia children and children in the control group. Second, gross motor function classification system (GMFCS) was used to classify the fourteen monoplegia children among whom there were five GMFCS Ⅰ patients and nine GMFCS Ⅱ patients. The differences of mfVEP were analyzed between the two GMFCS groups. ResultsThe amplitude and latency of mfVEP in children with CP showed gradual changes similar to those in the normal children. The amplitudes were decreasing and the latencies were delaying from the first eccentricity to the sixth eccentricity. The amplitudes in children with CP were lower than those in the control group in the first to the third eccentricities for both eyes (P＜0.05), and latency of left eye was delayed in the first eccentricity in children with CP (P=0.045). No difference was found between the two GMFCS groups (P>0.05) except the amplitude of the first eccentricity (P=0.043). ConclusionsThe results of mfVEP show significant differences of amplitude and latency between CP and normal children, suggesting the existence of visual pathway impairments in cerebral palsy children. The results of mfVEP can provide an objective basis of visual impairments for cerebral palsy children.