ELECTRO-PHYSIOLOGICAL CHARACTERIZATION OF REMOTE CHEMICAL SYNAPSES
ELECTRO-PHYSIOLOGICAL CHARACTERIZATION OF REMOTE CHEMICAL SYNAPSES
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DOI：
10.1152/jn.1982.47.4.606
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发表时间：
1982-01-01
影响因子：
2.5
通讯作者：
JOHNSTON, D
中科院分区：
文献类型：
--
作者：
CARNEVALE, NT;JOHNSTON, D
位于树突上的给定突触与锋电位触发区之间的电紧张耦合程度是该突触对神经元放电的相对影响的主要决定因素。突触和记录位点之间的电紧张耦合程度也影响该突触的生物物理性质的测量。本文提出了一种用于确定任何给定的远程突触输入和细胞内测量的位点之间的电紧张耦合的理论方法。方程推导出的突触输入的电生理特性。该方法是独立的许多假设的等效电缆模型。神经元被描绘为线性2端口电网络，其中电位记录和电流注入的位点表示一个端口，突触输入表示另一个端口。导出了网络的3个参数：k12，k21和k2。k12是记录位点（通常是索马）和突触下膜之间的电紧张耦合系数。它定义了从索马到突触的稳态电压衰减的程度。它还定义了当电压钳施加到索马时，从突触到索马的电荷转移和从突触到索马的稳态电流衰减。k21是突触和索马之间的电紧张耦合系数。它定义了从突触到索马的稳态电压衰减程度以及从索马到突触的电荷转移和电流衰减。k2是k12和k21的乘积。如何K12，K21和K2可以确定经验，和固有的假设在各种推导和本方法，以减少潜在的错误，进行了讨论。
The degree of electrotonic coupling between a given synapse located on a dendrite and the spike trigger zone is a major determinant of the relative influence of that synapse on neuronal firing. The degree of electrotonic coupling between a synapse and the recording site also influences the measurement of the biophysical properties of that synapse. A theoretical method for determining the electrotonic coupling between any given remote synaptic input and the site of intracellular measurements is presented. Equations were derived for the electrophysiological characterization of that synaptic input. The approach is independent of many of the assumptions of the equivalent cable model. The neuron is depicted as a linear 2-port electrical network, with the site of potential recording and current injection representing one port and the synaptic input the other. Derivations are presented for 3 parameters of the network: k12, k21 and k2. k12 is the electrotonic coupling coefficient between the recording site (usually the soma) and the subsynaptic membrane. It defines the degree of steady-state voltage decay from soma to synapse. It also defines the charge transfer from synapse to soma and the steady-state current decay from synapse to soma when a voltage clamp is applied to the soma. k21 is the electrotonic coupling coefficient between the synapse and the soma. It defines the degree of steady-state voltage decay from synapse to soma and the charge transfer and current decay from soma to synapse. k2 is the product of k12 and k21. How k12, k21 and k2 can be determined empirically, and the assumptions inherent in the various derivations and present methods for reducing potential errors, are discussed.