AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into ...AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine ceils with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels （KATP）, voltage-dependent potassium channels （Kv）, and voltage-dependent calcium channels （KcA） in β-cells were identified by patch clamp technique. RESULTS： After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly （MTT value from 0.024 ±0.003 to 3.028±0.003, insulin secretion from 2.6±0.6 to 3.1±0.8 mIU/L）. Then MTT value and insulin secretion increased quickly from d 5 to d 10 （MTT value from 0.028 ±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8 to 18.3±2.6 mIU/L）, then reached high plateau （MTT value 〉0.052±0.008, insulin secretion 〉18.3±2.6 mIU/L）. In contrast, for the isolated adult pancreatic islet cells, both insulin release and MTT value were stable in the first 4 d （MTT value from 0.029±0.01 to 0.031±0.011, insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L）, but afterwards they reduced gradually （MTT value 〈0.031 ±0.011, insulin secretion 〈8.2±1.5 mIU/L）, and the pancreatic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP, Kv, and KCA. CONCLUSION： Islet cells differentiated from neonatal pancreatic duct cells with the new natural protocol are more advantageous in performing patch clamp study over the isolated adult pancreatic islet cells.展开更多
The patch clamp recording technique in vivois a blind patch clamp recording methods to record the current of the spinal or cereral neurons of anaes：hesia （ or awake） animals. This technique can be used to study the...The patch clamp recording technique in vivois a blind patch clamp recording methods to record the current of the spinal or cereral neurons of anaes：hesia （ or awake） animals. This technique can be used to study the synaptic function and plasticity in central nervous system in vivoin order to understand the physiological properties of the ion channels from an integrated point of view. The advantage of this technique have already presented itself in the study of the synaptic transmission and nervous network. Nowadays, in vivo patch whole-cell recording technique in combination with other techniques is becoming a common method in the research fields.展开更多
To study the electrophysiologic effects of endothelin-1 (ET-1), we used patch clamp and glass microelectrode techniques to investigate the effects of ET-1 on cardiac L-Ica, Ik and Ik2 in guinea pig ventricular myocyte...To study the electrophysiologic effects of endothelin-1 (ET-1), we used patch clamp and glass microelectrode techniques to investigate the effects of ET-1 on cardiac L-Ica, Ik and Ik2 in guinea pig ventricular myocytes. The prolongation of APD50, was induced and EADs was triggered by 50 nM ET-1 perfusion. L-lea and Ik were enhanced by various ET-1 concentration from 1 to 50 nM with dose-dependence. Their steady-state activations of L-Iea and Ik shifted left with ET-1 concentration increments. ET-1 elicited a kind of GTP- dependent inward rectifier K current having a mean conductance of 82.36±1.27 pS. The open time and close time ( both interburst intervals and burst durations ) abbreviated with ET-1 concentration increase. The results suggested that EADs -ET evoked was ascribed to the prolongation on the plateau level, which resulted from L-Ica inhancement. The ET- evoked inward rectifier K+ current should be further studied.展开更多
Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl^- channels inhuman sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembl...Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl^- channels inhuman sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembled intoliposome bilayer, and the liposomes were fused into giant liposomes with a diameter more than 10μm by dehydration-rehydration procedure. The giant liposomes were used to study the Cl^- channel activities by patch-clamp technique.Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine)-Cl (bath 100//pipette 200 mmol/L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS,(117.0±5.7) pS and (144.7±4.5) pS, respectively, were detected. Their activities were voltage-dependent and allwere blocked by SITS (4-acetamido-4'-isothiocyanato-stilbene-2', 2'-disulfonic acid) in a concentration-dependentmanner. By constructing the open and close dwell time distribution histograms and then fitting them with exponentialfunction, two time constants were obtained in both the open and the close states. The burst activity and conductancesubstate of the channels were observed. Conclusion; There exist three kinds of Cl^- channels with different conduc-tance in human sperm membrane at least. (Asian J Androl 2001 Sep; 3: 185 - 191)展开更多
Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr w...Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr were increased when the concentration of Cu^2＋ was lower than 2 × 10^-5 and 10^-5 tool/L, respectively, and increased ratio was decreased with increasing Cu^2＋concentration in the bath solutions. When the concentration continued to increase to 5× 10^-5 and 2 × 10^- 5 mol/L, the currents were hardly changed, while the concentration was more than 10^-4 and 5 × 10^-5 mol/L, the currents were inhibited remarkably. Cu^2＋ （10^-5 mol/L） did not affect the activation and inactivation process of Ito. The activation curve of Idr was shifted toward positive potential, but 10^-5 mol/L Cu^2＋did not affect slope factor. According to these results, it was considered that Cu^2＋at low concentration in the bath solution could promote Ito and Idr while at high concentration could inhibit them, and change of amplitude was different with different membrane voltage. Conclusion was drawn： Cu^2＋may be involved in the pathophysiologic mechanism of diseases with neuropathological components.展开更多
The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into a...The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise. A new algorithm called EHMM (Extended HMM) algorithm is proposed, and mainly validated by simulation. Results show that it’s effective.展开更多
Background The myocardial ATP sensitive potassium channel （KATP channel） has been known for more than two decades, the properties of this channel have been intensively investigated, especially the myocardial protect...Background The myocardial ATP sensitive potassium channel （KATP channel） has been known for more than two decades, the properties of this channel have been intensively investigated, especially the myocardial protection effect by opening this channel. Numerous studies, including hypothermic, using KATP agonists to achieve a hyperpolarizing cardioplegic arrest, have shown a better myocardial protection than potassium arrest. However, there is no evidence showing that KATP channel could be opened by its agonists under profound hypothermia. We investigated the effect of temperature on activation of myocardial KATP channel by nicorandil.Methods Isolated ventricular myocytes were obtained by collagenase digestion of the hearts of guinea pigs and stored in KB solution at 4℃. With a steady ground current, the myocytes were perfused with 1 mmol/L nicorandil until a steady IKATP occurred. Then the cells were perfused with 1 mmol/L nicorandil plus 1 μmol/L glybenclamide. Currents signals were recorded on whole cells using patch clamp technique at several temperatures. The temperature of the bath solution around myocytes was monitored and was controlled at 4℃, 10℃, 20℃, 25℃ and 35℃ respectively. About 10 cells were tested at each temperature, the cells were considered useful only when the outward current could be induced by nicorandil and blocked by glybenclamide. All data were analyzed using Graphpad PRISM 3.0 （Graphpad, San Diego, CA, USA）. Nonlinear curve fitting was done in Clampfit （Axon） or Sigmaplot （SPSS）.Results At 4℃, 10℃, 20℃, 25℃ and 35℃, the time needed to open the myocardial KATP channel was （81.0±0） minutes, （50.54±11.7） minutes, （28.84±2.3） minutes, （9.4± 10.2） minutes and （2.3± 1.0） minutes respectively （P=0.003）. The linear relationship between temperature and time needed to open the channel was y （min） = （4348.790±124.277x）/60, where y （min） is time needed to open KATP channel, x is temperature, correlation coefficient r =-0.942 （P=0.00）, regression coefficient b =-124.277 （P=0.00）. The current densities among different temperatures were statistically different （P=0.022）, the current density was greater after the activation of KATP channel at higher temperatures. The lower the temperature, the fewer cells in which KATP channels could be opened. At 4℃, only one cell in which the KATP channel could be opened, took a quite long time （81 minutes）and the Ⅰ-Ⅴ curve was quite untypical.Conclusions KATP channel activated by nicorandil is temperature dependent and the temperature linearly related to time needed to open KATP channel; the lower the temperature, the longer the time needed to open channel and the smaller the current density. At profound hypothermia, it is difficult to activate KATP channels.展开更多
We used whole-vacuolar patch-clamp recording mode to study the action mechanism of La3+ to Slow Vacuolar (SV) channels for the first time. We recorded SV channel currents of Xinlimei (Raphanus satirus L.) vacuolars. T...We used whole-vacuolar patch-clamp recording mode to study the action mechanism of La3+ to Slow Vacuolar (SV) channels for the first time. We recorded SV channel currents of Xinlimei (Raphanus satirus L.) vacuolars. The minimum activation potentials of voltage-dependent SV channels tied in 25+/-5 mV. The increase in cytoplasmic Ca2+ led to enhancement of SV-type currents. It was found that the threshold potential of activation shifted towards more depolarized values whenever cytoplasmic Ca2+ was increased. When 10(-10) mol/L free La3+ was added to the bath, SV-type current was suppressed by 60 similar to 75%. These data showed La3+ reduced ion permeabilities of Xinlimei root vacuolar membrane.展开更多
One kind of novel BLMs was fabricated by patch-clamp pipette technology characterized in considerably sensitive to changes of electrochemical parameters.Detectiye currents and voltage presented linear relationship whe...One kind of novel BLMs was fabricated by patch-clamp pipette technology characterized in considerably sensitive to changes of electrochemical parameters.Detectiye currents and voltage presented linear relationship when BLMs was formed and it could be confirmed by Gramicidin method.Ion current was increased by dihexyl (C_ (12)) modified ssDNA fixed on the BLMs and also indicated linear relationship to ssDNA's concentration due to the interaction of (C_ 12)-ssDNA and BLMs.Further more,the regression equations were different from BLMs fixed with ssDNA probe and a blank control BLM in the same experimental conditions.The ssDNA probe was successfully fixed on patch-clamp pipette supported-BLMs.Based on our studies,a biosensor with reactive element of patch-clamp pipette-supported BLMs has been established.展开更多
背景:膜片钳技术作为研究离子通道的“金标准”,已有40多年的发展历史。然而,科研机构的研究内容相对独立,没有对现有研究成果进行系统总结,导致现有研究存在重复性高、创新性弱的现象。因此,急需对膜片钳技术做一个全面的回顾,以明晰...背景:膜片钳技术作为研究离子通道的“金标准”,已有40多年的发展历史。然而,科研机构的研究内容相对独立,没有对现有研究成果进行系统总结,导致现有研究存在重复性高、创新性弱的现象。因此,急需对膜片钳技术做一个全面的回顾,以明晰现今的研究现状、热点和未来发展方向。目的:总结近10年膜片钳技术领域的研究现状和发展趋势。方法:使用Web of Science核心合集数据库收集了2013-2023年关于膜片钳技术的出版物。采用CiteSpace和VOSviewer软件对出版物数量进行量化分析,并分析文献条目网络,包括国家、机构、期刊、作者、关键词、高被引文献和共被引参考文献。结果与结论:①近10年间,膜片钳技术领域研究已逐步进入稳定发展阶段。②中国和美国是这方面的领先国家,中国科学院是具有核心影响力的机构,《Journal of Neuroscience》是主要出版刊物,PARK,WON SUN团队(韩国全北国立大学)和CHU,LI团队(中国河北省心脑血管病中医药防治研究重点实验室)在该领域作出了杰出的贡献,但团队之间的协作与交流较少,尚未形成网络合作模式。③膜片钳技术主要应用在神经系统的电生理特性及其疾病的病理机制方面,是研究人员持续关注的焦点。④在心血管系统电生理特性及其疾病病理机制的研究方面,对原代心肌细胞、诱导多能干细胞衍生的心肌细胞的电生理特性和心房颤动、心脏毒性、心源性猝死和高血压等心血管疾病的病理机制方面的研究,是近几年来研究的热点。⑤在膜片钳技术与其他生物技术的结合应用方面,关注的是与光遗传学、双光子钙成像等技术的交叉融合,将是一个重要的研究方向。⑥在药物筛选及治疗靶点的识别研究方面,尤其对于膜片钳技术和中药复方的研究,将成为未来组分中药研究中的一大助力。展开更多
该研究旨在探究小功率无线电能传输(wireless power transmission,WPT)系统对小鼠海马CA1区神经元兴奋性的影响。将小鼠分为对照组和辐射组(2周组、4周组、6周组),通过莫里斯水迷宫实验、光纤光度实验、HE染色实验、膜片钳实验观察小鼠...该研究旨在探究小功率无线电能传输(wireless power transmission,WPT)系统对小鼠海马CA1区神经元兴奋性的影响。将小鼠分为对照组和辐射组(2周组、4周组、6周组),通过莫里斯水迷宫实验、光纤光度实验、HE染色实验、膜片钳实验观察小鼠工作记忆能力、Ca^(2+)信号强度、海马锥体细胞数量、动作电位的变化以及瞬时外向K^(+)通道电流(I_(A))和延迟整流K^(+)通道电流(I_(K))的变化。莫里斯水迷宫实验结果显示,小功率WPT电磁环境不会对小鼠的工作记忆能力产生影响;光纤光度实验以及HE染色实验显示,小功率WPT电磁环境可能促进了海马CA1区神经元集群的放电活动,导致了荧光信号强度的增加。这表明电磁环境对Ca^(2+)浓度的调节可能增加了海马CA1区神经元放电活动次数,增强了海马CA1区神经元的兴奋性。随着辐射时间的增加,荧光信号的峰值逐渐下降,表明小鼠海马锥体细胞适应了小功率WPT电磁环境;小功率WPT电磁环境提高了小鼠海马CA1区的神经元的静息膜电位,缩短了动作电位的半波宽,降低了动作电位阈值,加快了海马CA1区的神经元动作电位的发放频率,促进了海马CA1区的神经元动作电位的发放,提高了海马CA1区的神经元的兴奋性;小功率WPT电磁环境会令细胞膜上的瞬时外向钾通道的激活过程受到抑制、延迟整流钾通道的激活特性向去极化方向移动,减少细胞内K^(+)的外流,进而增强海马CA1区神经元兴奋性。小功率WPT电磁环境可促进海马锥体细胞的放电活动,抑制I_(A)与I_(K)的激活过程,I_(A)通道的激活曲线向去极化方向偏移,从而增强神经元兴奋性。展开更多
基金Supported by the National Natural Science Foundation of China,No. 30472254
文摘AIM： To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study. METHODS： The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine ceils with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels （KATP）, voltage-dependent potassium channels （Kv）, and voltage-dependent calcium channels （KcA） in β-cells were identified by patch clamp technique. RESULTS： After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly （MTT value from 0.024 ±0.003 to 3.028±0.003, insulin secretion from 2.6±0.6 to 3.1±0.8 mIU/L）. Then MTT value and insulin secretion increased quickly from d 5 to d 10 （MTT value from 0.028 ±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8 to 18.3±2.6 mIU/L）, then reached high plateau （MTT value 〉0.052±0.008, insulin secretion 〉18.3±2.6 mIU/L）. In contrast, for the isolated adult pancreatic islet cells, both insulin release and MTT value were stable in the first 4 d （MTT value from 0.029±0.01 to 0.031±0.011, insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L）, but afterwards they reduced gradually （MTT value 〈0.031 ±0.011, insulin secretion 〈8.2±1.5 mIU/L）, and the pancreatic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP, Kv, and KCA. CONCLUSION： Islet cells differentiated from neonatal pancreatic duct cells with the new natural protocol are more advantageous in performing patch clamp study over the isolated adult pancreatic islet cells.
文摘The patch clamp recording technique in vivois a blind patch clamp recording methods to record the current of the spinal or cereral neurons of anaes：hesia （ or awake） animals. This technique can be used to study the synaptic function and plasticity in central nervous system in vivoin order to understand the physiological properties of the ion channels from an integrated point of view. The advantage of this technique have already presented itself in the study of the synaptic transmission and nervous network. Nowadays, in vivo patch whole-cell recording technique in combination with other techniques is becoming a common method in the research fields.
文摘To study the electrophysiologic effects of endothelin-1 (ET-1), we used patch clamp and glass microelectrode techniques to investigate the effects of ET-1 on cardiac L-Ica, Ik and Ik2 in guinea pig ventricular myocytes. The prolongation of APD50, was induced and EADs was triggered by 50 nM ET-1 perfusion. L-lea and Ik were enhanced by various ET-1 concentration from 1 to 50 nM with dose-dependence. Their steady-state activations of L-Iea and Ik shifted left with ET-1 concentration increments. ET-1 elicited a kind of GTP- dependent inward rectifier K current having a mean conductance of 82.36±1.27 pS. The open time and close time ( both interburst intervals and burst durations ) abbreviated with ET-1 concentration increase. The results suggested that EADs -ET evoked was ascribed to the prolongation on the plateau level, which resulted from L-Ica inhancement. The ET- evoked inward rectifier K+ current should be further studied.
文摘Aim: To record the single-channel currents and characterize the electrophysiological properties of the Cl^- channels inhuman sperm membrane. Methods: The membrane proteins extracted from the human sperm were reassembled intoliposome bilayer, and the liposomes were fused into giant liposomes with a diameter more than 10μm by dehydration-rehydration procedure. The giant liposomes were used to study the Cl^- channel activities by patch-clamp technique.Results: By patch clamping the giant liposome in an asymmetric NMDG (N-methyl-D-glucamine)-Cl (bath 100//pipette 200 mmol/L) solution system, three kinds of single-channel events with unit conductances of (74.1 ± 8.3) pS,(117.0±5.7) pS and (144.7±4.5) pS, respectively, were detected. Their activities were voltage-dependent and allwere blocked by SITS (4-acetamido-4'-isothiocyanato-stilbene-2', 2'-disulfonic acid) in a concentration-dependentmanner. By constructing the open and close dwell time distribution histograms and then fitting them with exponentialfunction, two time constants were obtained in both the open and the close states. The burst activity and conductancesubstate of the channels were observed. Conclusion; There exist three kinds of Cl^- channels with different conduc-tance in human sperm membrane at least. (Asian J Androl 2001 Sep; 3: 185 - 191)
基金Project supported by the National Natural Science Foundation of China （No. 30470408）.
文摘Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr were increased when the concentration of Cu^2＋ was lower than 2 × 10^-5 and 10^-5 tool/L, respectively, and increased ratio was decreased with increasing Cu^2＋concentration in the bath solutions. When the concentration continued to increase to 5× 10^-5 and 2 × 10^- 5 mol/L, the currents were hardly changed, while the concentration was more than 10^-4 and 5 × 10^-5 mol/L, the currents were inhibited remarkably. Cu^2＋ （10^-5 mol/L） did not affect the activation and inactivation process of Ito. The activation curve of Idr was shifted toward positive potential, but 10^-5 mol/L Cu^2＋did not affect slope factor. According to these results, it was considered that Cu^2＋at low concentration in the bath solution could promote Ito and Idr while at high concentration could inhibit them, and change of amplitude was different with different membrane voltage. Conclusion was drawn： Cu^2＋may be involved in the pathophysiologic mechanism of diseases with neuropathological components.
文摘The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model (HMM) algorithm has been used to convert the low signal noise ratio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise. A new algorithm called EHMM (Extended HMM) algorithm is proposed, and mainly validated by simulation. Results show that it’s effective.
基金This work was supported by a grant from the Natural Science Foundation of China (No. 30371374).
文摘Background The myocardial ATP sensitive potassium channel （KATP channel） has been known for more than two decades, the properties of this channel have been intensively investigated, especially the myocardial protection effect by opening this channel. Numerous studies, including hypothermic, using KATP agonists to achieve a hyperpolarizing cardioplegic arrest, have shown a better myocardial protection than potassium arrest. However, there is no evidence showing that KATP channel could be opened by its agonists under profound hypothermia. We investigated the effect of temperature on activation of myocardial KATP channel by nicorandil.Methods Isolated ventricular myocytes were obtained by collagenase digestion of the hearts of guinea pigs and stored in KB solution at 4℃. With a steady ground current, the myocytes were perfused with 1 mmol/L nicorandil until a steady IKATP occurred. Then the cells were perfused with 1 mmol/L nicorandil plus 1 μmol/L glybenclamide. Currents signals were recorded on whole cells using patch clamp technique at several temperatures. The temperature of the bath solution around myocytes was monitored and was controlled at 4℃, 10℃, 20℃, 25℃ and 35℃ respectively. About 10 cells were tested at each temperature, the cells were considered useful only when the outward current could be induced by nicorandil and blocked by glybenclamide. All data were analyzed using Graphpad PRISM 3.0 （Graphpad, San Diego, CA, USA）. Nonlinear curve fitting was done in Clampfit （Axon） or Sigmaplot （SPSS）.Results At 4℃, 10℃, 20℃, 25℃ and 35℃, the time needed to open the myocardial KATP channel was （81.0±0） minutes, （50.54±11.7） minutes, （28.84±2.3） minutes, （9.4± 10.2） minutes and （2.3± 1.0） minutes respectively （P=0.003）. The linear relationship between temperature and time needed to open the channel was y （min） = （4348.790±124.277x）/60, where y （min） is time needed to open KATP channel, x is temperature, correlation coefficient r =-0.942 （P=0.00）, regression coefficient b =-124.277 （P=0.00）. The current densities among different temperatures were statistically different （P=0.022）, the current density was greater after the activation of KATP channel at higher temperatures. The lower the temperature, the fewer cells in which KATP channels could be opened. At 4℃, only one cell in which the KATP channel could be opened, took a quite long time （81 minutes）and the Ⅰ-Ⅴ curve was quite untypical.Conclusions KATP channel activated by nicorandil is temperature dependent and the temperature linearly related to time needed to open KATP channel; the lower the temperature, the longer the time needed to open channel and the smaller the current density. At profound hypothermia, it is difficult to activate KATP channels.
基金The authors acknowledge the support of the National Natural Science Foundation of ChinaProvincial Natural Science Foundation of Shanxi.
文摘We used whole-vacuolar patch-clamp recording mode to study the action mechanism of La3+ to Slow Vacuolar (SV) channels for the first time. We recorded SV channel currents of Xinlimei (Raphanus satirus L.) vacuolars. The minimum activation potentials of voltage-dependent SV channels tied in 25+/-5 mV. The increase in cytoplasmic Ca2+ led to enhancement of SV-type currents. It was found that the threshold potential of activation shifted towards more depolarized values whenever cytoplasmic Ca2+ was increased. When 10(-10) mol/L free La3+ was added to the bath, SV-type current was suppressed by 60 similar to 75%. These data showed La3+ reduced ion permeabilities of Xinlimei root vacuolar membrane.
文摘One kind of novel BLMs was fabricated by patch-clamp pipette technology characterized in considerably sensitive to changes of electrochemical parameters.Detectiye currents and voltage presented linear relationship when BLMs was formed and it could be confirmed by Gramicidin method.Ion current was increased by dihexyl (C_ (12)) modified ssDNA fixed on the BLMs and also indicated linear relationship to ssDNA's concentration due to the interaction of (C_ 12)-ssDNA and BLMs.Further more,the regression equations were different from BLMs fixed with ssDNA probe and a blank control BLM in the same experimental conditions.The ssDNA probe was successfully fixed on patch-clamp pipette supported-BLMs.Based on our studies,a biosensor with reactive element of patch-clamp pipette-supported BLMs has been established.
文摘背景:膜片钳技术作为研究离子通道的“金标准”,已有40多年的发展历史。然而,科研机构的研究内容相对独立,没有对现有研究成果进行系统总结,导致现有研究存在重复性高、创新性弱的现象。因此,急需对膜片钳技术做一个全面的回顾,以明晰现今的研究现状、热点和未来发展方向。目的:总结近10年膜片钳技术领域的研究现状和发展趋势。方法:使用Web of Science核心合集数据库收集了2013-2023年关于膜片钳技术的出版物。采用CiteSpace和VOSviewer软件对出版物数量进行量化分析,并分析文献条目网络,包括国家、机构、期刊、作者、关键词、高被引文献和共被引参考文献。结果与结论:①近10年间,膜片钳技术领域研究已逐步进入稳定发展阶段。②中国和美国是这方面的领先国家,中国科学院是具有核心影响力的机构,《Journal of Neuroscience》是主要出版刊物,PARK,WON SUN团队(韩国全北国立大学)和CHU,LI团队(中国河北省心脑血管病中医药防治研究重点实验室)在该领域作出了杰出的贡献,但团队之间的协作与交流较少,尚未形成网络合作模式。③膜片钳技术主要应用在神经系统的电生理特性及其疾病的病理机制方面,是研究人员持续关注的焦点。④在心血管系统电生理特性及其疾病病理机制的研究方面,对原代心肌细胞、诱导多能干细胞衍生的心肌细胞的电生理特性和心房颤动、心脏毒性、心源性猝死和高血压等心血管疾病的病理机制方面的研究,是近几年来研究的热点。⑤在膜片钳技术与其他生物技术的结合应用方面,关注的是与光遗传学、双光子钙成像等技术的交叉融合,将是一个重要的研究方向。⑥在药物筛选及治疗靶点的识别研究方面,尤其对于膜片钳技术和中药复方的研究,将成为未来组分中药研究中的一大助力。
文摘该研究旨在探究小功率无线电能传输(wireless power transmission,WPT)系统对小鼠海马CA1区神经元兴奋性的影响。将小鼠分为对照组和辐射组(2周组、4周组、6周组),通过莫里斯水迷宫实验、光纤光度实验、HE染色实验、膜片钳实验观察小鼠工作记忆能力、Ca^(2+)信号强度、海马锥体细胞数量、动作电位的变化以及瞬时外向K^(+)通道电流(I_(A))和延迟整流K^(+)通道电流(I_(K))的变化。莫里斯水迷宫实验结果显示,小功率WPT电磁环境不会对小鼠的工作记忆能力产生影响;光纤光度实验以及HE染色实验显示,小功率WPT电磁环境可能促进了海马CA1区神经元集群的放电活动,导致了荧光信号强度的增加。这表明电磁环境对Ca^(2+)浓度的调节可能增加了海马CA1区神经元放电活动次数,增强了海马CA1区神经元的兴奋性。随着辐射时间的增加,荧光信号的峰值逐渐下降,表明小鼠海马锥体细胞适应了小功率WPT电磁环境;小功率WPT电磁环境提高了小鼠海马CA1区的神经元的静息膜电位,缩短了动作电位的半波宽,降低了动作电位阈值,加快了海马CA1区的神经元动作电位的发放频率,促进了海马CA1区的神经元动作电位的发放,提高了海马CA1区的神经元的兴奋性;小功率WPT电磁环境会令细胞膜上的瞬时外向钾通道的激活过程受到抑制、延迟整流钾通道的激活特性向去极化方向移动,减少细胞内K^(+)的外流,进而增强海马CA1区神经元兴奋性。小功率WPT电磁环境可促进海马锥体细胞的放电活动,抑制I_(A)与I_(K)的激活过程,I_(A)通道的激活曲线向去极化方向偏移,从而增强神经元兴奋性。
