目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状...目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。展开更多
Synchronous firing of neurons is thought to be important for information communication in neuronal networks. This paper investigates the complete and phase synchronization in a heterogeneous small-world chaotic Hindma...Synchronous firing of neurons is thought to be important for information communication in neuronal networks. This paper investigates the complete and phase synchronization in a heterogeneous small-world chaotic Hindmarsh Rose neuronal network. The effects of various network parameters on synchronization behaviour are discussed with some biological explanations. Complete synchronization of small-world neuronal networks is studied theoretically by the master stability function method. It is shown that the coupling strength necessary for complete or phase synchronization decreases with the neuron number, the node degree and the connection density are increased. The effect of heterogeneity of neuronal networks is also considered and it is found that the network heterogeneity has an adverse effect on synchrony.展开更多
A complete method of synchronization technology of bistatic radar using global position system （GPS） is presented. The pulse per second signal （1PPS） is elaborately modified to increase the time synchronization pr...A complete method of synchronization technology of bistatic radar using global position system （GPS） is presented. The pulse per second signal （1PPS） is elaborately modified to increase the time synchronization precision and keep loop locking. A very high time synchronization precision is achieved. Using the modified 1PPS to discipline the local OCXO, the reference frequency signal achieves both high long term stability （LTS） and short term stability （STS） properties. An algorithm, named phase abrupt change CFAR is presented to restrain the 1PPS phase abrupt change and keep loop locking. The experimental results indicate that this time and frequency synchronization method is effective and the time synchronization precision of the synchronization system can be improved from ±100 ns to ±25 ns. In addition, the phase noise is improved to 20 dB.展开更多
文摘目的:通过观察运动疲劳后大鼠初级运动皮层M1-纹状体通路局部场电位(Local field potential,LFPs)相位同步振荡活动,结合DA信号系统在运动疲劳后代谢表达变化,探讨皮层-纹状体通路电信号编码在运动疲劳中枢调控中的机制及其与黑质-纹状体DA系统的协同作用。方法:采用Wistar大鼠建立运动疲劳模型,分为对照组(CG),7天力竭运动即刻组(7FG)以及7天重复力竭运动24 h恢复组(24RG)。采用在体多通道电生理同步记录技术,结合实时视频录像观察M1及纹状体LFPs电振荡活动,分析皮层M1-纹状体同步振荡的相干性;采用免疫组化检测纹状体背外侧区DA受体及相关转运体蛋白在运动疲劳前后的表达。结果:1)与CG组相比,7FG组皮层M1区及纹状体α及β振荡增强(P<0.05),恢复24 h后较7FG组PSD值显著下降(P<0.05),且皮层M1-纹状体α及β振荡相干系数变大、同步性增强(P<0.05);2)与7FG组相比,24RG组相干系数及STWA比率均显著下降(P<0.05);3)与CG组相比,7FG组纹状体背外侧区D2DR表达降低,VMAT2表达上调且差异具有显著性(P<0.05);4)与7FG组相比,24RG组背外侧纹状体区D1DR表达显著降低(P<0.05)。结论:运动疲劳后,D2DR减少可能是导致突触后致密物厚度变化的原因之一,造成纹状体GABA能活动增强,使纹状体电活动增强,反馈至皮层影响皮层综合信号的输出,进而影响大鼠行为活动能力。表明皮层M1和纹状体脑区之间同步振荡活动的改变可能是运动疲劳症状产生的原因之一,且D2DR作为黑质-纹状体DA信号系统的关键受体,可作为改善运动疲劳的干预靶点。
基金supported by the National Natural Science Foundation of China (Grant No 10872014)
文摘Synchronous firing of neurons is thought to be important for information communication in neuronal networks. This paper investigates the complete and phase synchronization in a heterogeneous small-world chaotic Hindmarsh Rose neuronal network. The effects of various network parameters on synchronization behaviour are discussed with some biological explanations. Complete synchronization of small-world neuronal networks is studied theoretically by the master stability function method. It is shown that the coupling strength necessary for complete or phase synchronization decreases with the neuron number, the node degree and the connection density are increased. The effect of heterogeneity of neuronal networks is also considered and it is found that the network heterogeneity has an adverse effect on synchrony.
基金the National Ministry Innovation Foundation (7130302)
文摘A complete method of synchronization technology of bistatic radar using global position system （GPS） is presented. The pulse per second signal （1PPS） is elaborately modified to increase the time synchronization precision and keep loop locking. A very high time synchronization precision is achieved. Using the modified 1PPS to discipline the local OCXO, the reference frequency signal achieves both high long term stability （LTS） and short term stability （STS） properties. An algorithm, named phase abrupt change CFAR is presented to restrain the 1PPS phase abrupt change and keep loop locking. The experimental results indicate that this time and frequency synchronization method is effective and the time synchronization precision of the synchronization system can be improved from ±100 ns to ±25 ns. In addition, the phase noise is improved to 20 dB.
