Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （...Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （S1 area） . Methods Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid （95% O2 and 5% CO2） , and were mounted on a Med64 probe （64 electrodes, 8×8 array） for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes. Results The local intracortical connection, which is involved in mediation of downward information flow across layers II-VI, was identified by electrical stimulation （ES） at layers II-III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II-IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus （CS） applied within layer IV of the S1 area could success-fully induce long-term potentiation （LTP） in 5 of the 6 slices （83.3%） , while the same CS application at layers II-III induced no LTP in any of the 6 tested slices. Conclusion The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices： one is the intracortical circuit （ICC） formed by interlaminar connections from layers II-III, and the other is the thalamocortical circuit （TCC） mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plastic展开更多
目的探讨慢性下腰腿痛(LBLP)患者静息态初级躯体感觉皮层的功能连接情况。方法采用3.0 T MRI对26例椎间盘突出所致LBLP患者(LBLP组)和34例健康志愿者(对照组)进行静息态fMRI扫描,使用脑成像数据处理及分析助手V3.0对静息态fMRI数据进行...目的探讨慢性下腰腿痛(LBLP)患者静息态初级躯体感觉皮层的功能连接情况。方法采用3.0 T MRI对26例椎间盘突出所致LBLP患者(LBLP组)和34例健康志愿者(对照组)进行静息态fMRI扫描,使用脑成像数据处理及分析助手V3.0对静息态fMRI数据进行预处理。以双侧初级躯体感觉皮层(S1leg:初级躯体感觉皮层足代表区)作为种子点,进行功能连接分析并采用两样本t检验与健康对照组进行组间比较。将功能连接系数有显著性差异的脑区分别选为感兴趣区,以峰值坐标为中心提取球形区域内功能连接系数的平均值,与临床评估(视觉模拟量表评分、日本骨科协会评分、两点触觉辨别测试等)参数进行偏相关分析。结果与对照组相比,左侧S1leg和左侧前扣带回功能连接减弱(体素水平P<0.01,簇水平<0.05,GRF校正),而右侧S1leg和双侧小脑后叶功能连接增强(体素水平P<0.01,簇水平<0.05,GRF校正)。在LBLP患者组,右侧S1leg和双侧小脑后叶的功能连接系数与Barthel指数呈正相关(r=0.422,P=0.040)、与左手两点触觉辨别测试评分呈负相关(r=-0.447,P=0.028)、与右足两点触觉辨别测试评分呈负相关(r=-0.510,P=0.011)。结论静息状态下慢性LBLP患者存在和临床症状相关的初级躯体感觉皮层功能连接异常。展开更多
基金supported by the National Basic Research Development Program(973)of China(No.2006CB500800)National Innovation Team Program of Ministry of Education(No.IRT0560)National Natural Science Foundation of China(No.30670692 and 30770668)
文摘Objective The well-established planar multi-electrode array recording technique was used to investigate neural circuits and temporal plasticity in the hindlimb representation of the rat primary somatosensory cortex （S1 area） . Methods Freshly dissociated acute brain slices of rats were subject to constant perfusion with oxygenated artificial cerebrospinal fluid （95% O2 and 5% CO2） , and were mounted on a Med64 probe （64 electrodes, 8×8 array） for simultaneous multi-site electrophysiological recordings. Current sources and sinks across all the 64 electrodes were transformed into two-dimensional current source density images by bilinear interpolation at each point of the 64 electrodes. Results The local intracortical connection, which is involved in mediation of downward information flow across layers II-VI, was identified by electrical stimulation （ES） at layers II-III. The thalamocortical connection, which is mainly involved in mediation of upward information flow across layers II-IV, was also characterized by ES at layer IV. The thalamocortical afferent projections were likely to make more synaptic contacts with S1 neurons than the intracortical connections did. Moreover, the S1 area was shown to be more easily activated and more intensively innervated by the thalamocortical afferent projections than by the intracortical connections. Finally, bursting conditioning stimulus （CS） applied within layer IV of the S1 area could success-fully induce long-term potentiation （LTP） in 5 of the 6 slices （83.3%） , while the same CS application at layers II-III induced no LTP in any of the 6 tested slices. Conclusion The rat hindlimb representation of S1 area is likely to have at least 2 patterns of neural circuits on brain slices： one is the intracortical circuit （ICC） formed by interlaminar connections from layers II-III, and the other is the thalamocortical circuit （TCC） mediated by afferent connections from layer IV. Besides, ICC of the S1 area is spatially limited, with less plastic
文摘目的探讨慢性下腰腿痛(LBLP)患者静息态初级躯体感觉皮层的功能连接情况。方法采用3.0 T MRI对26例椎间盘突出所致LBLP患者(LBLP组)和34例健康志愿者(对照组)进行静息态fMRI扫描,使用脑成像数据处理及分析助手V3.0对静息态fMRI数据进行预处理。以双侧初级躯体感觉皮层(S1leg:初级躯体感觉皮层足代表区)作为种子点,进行功能连接分析并采用两样本t检验与健康对照组进行组间比较。将功能连接系数有显著性差异的脑区分别选为感兴趣区,以峰值坐标为中心提取球形区域内功能连接系数的平均值,与临床评估(视觉模拟量表评分、日本骨科协会评分、两点触觉辨别测试等)参数进行偏相关分析。结果与对照组相比,左侧S1leg和左侧前扣带回功能连接减弱(体素水平P<0.01,簇水平<0.05,GRF校正),而右侧S1leg和双侧小脑后叶功能连接增强(体素水平P<0.01,簇水平<0.05,GRF校正)。在LBLP患者组,右侧S1leg和双侧小脑后叶的功能连接系数与Barthel指数呈正相关(r=0.422,P=0.040)、与左手两点触觉辨别测试评分呈负相关(r=-0.447,P=0.028)、与右足两点触觉辨别测试评分呈负相关(r=-0.510,P=0.011)。结论静息状态下慢性LBLP患者存在和临床症状相关的初级躯体感觉皮层功能连接异常。
