INTERPRETATION OF VOLTAGE-CLAMP MEASUREMENTS IN HIPPOCAMPAL-NEURONS
INTERPRETATION OF VOLTAGE-CLAMP MEASUREMENTS IN HIPPOCAMPAL-NEURONS
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DOI：
10.1152/jn.1983.50.2.464
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发表时间：
1983-01-01
影响因子：
2.5
通讯作者：
BROWN, TH
中科院分区：
文献类型：
--
作者：
JOHNSTON, D;BROWN, TH
评估了[豚鼠]海马锥体神经元局部和远端电导变化的电压钳测量的预期准确性，特别强调了对这些细胞的苔藓纤维突触输入。分析了这些神经元的无源电缆特性和最佳单微电极电压钳（SEC）电路的实际性能特征。模拟仿真被用来评估SEC的性能和不完美的空间钳位的后果。解剖测量的CA 3海马子区的横向切片，染色的快速高尔基或Timm方法。苔藓纤维突触位于透明层内的一条不连续的带中。从细胞索马体或锥体层到该带远端部分的平均距离为0.15 mm。锥体细胞的初级顶枝的平均直径为6.0 μ m。从这些细胞中的浓度为6.0 μ m。根据这些数据和树突的等效圆柱表示，计算出最远端的苔藓纤维突触位于与神经元胞体的平均电子距离不大于0.07的位置。构建了保留实际树突状分支的分支房室模型。从索马到苔藓纤维突触带末端的平均电子距离为0.06。SEC将产生0-300 Hz频带内电导变化的准确（平坦频率响应）电流测量，其包括苔藓纤维突触电导波形（其位于0-200 Hz范围内）的大部分功率谱。SEC系统将衰减远高于. apprx的频率分量。300赫兹
The expected accuracy of voltage-clamp measurements of local and remote conductance changes in [guinea pig] hippocampal pyramidal neruons was assessed, with special emphasis on the mossy fiber synaptic input to these cells. The passive cable properties of these neurons and the actual performance characteristics of the best available single-microelectrode voltage-clamp (SEC) circuit were analyzed. The analog simulations were used to assess the performance of the SEC and the consequences of imperfect space clamp. Anatomical measurements were made of the CA3 hippocampal subfield from transverse sections that were stained by the rapid Golgi or Timm methods. The mossy fiber synapses were located in a discrete band in the stratum lucidum. The average distance from the cell soma or stratum pyramidale to the distal portion of this band was 0.15 mm. The average diameter of the primary apical dendrites of the pyramidal cells was 6.0 .mu.m. From these cells was 6.0 .mu.m. From these data and an equivalent-cylinder representation of the dendrites, it was calculated that the most distal mossy fiber synapses were located at an average electronic distance no greater than 0.07 from the pyramida cell bodies. Branched compartmental models were constructed that preserved the actual dendritic arborization. The average electronic distance from the soma to the end of the mossy fiber synaptic zone was 0.06. The SEC will yield accurate (flat frequency response) current measurements for conductance changes within a frequency band of 0-300 Hz, which includes most of the power spectrum for a mossy fiber synaptic-conductance waveform (which lies in the range of 0-200 Hz). The SEC system will attenuate frequency components much higher than .apprx. 300 Hz.