Effective synaptic current can be estimated from measurements of neuronal discharge.
Effective synaptic current can be estimated from measurements of neuronal discharge.
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有效突触电流可以通过神经元放电的测量来估计。
DOI：
10.1152/jn.1992.68.3.964
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发表时间：
1992
影响因子：
2.5
通讯作者：
Binder,MD
中科院分区：
文献类型：
--
作者：
Powers,RK;Robinson,FR;Konodi,MA;Binder,MD
1.运动神经元如何将突触输入转化为锋电位序列输出的基本问题仍然没有得到解决，尽管它们的形态学，电生理学和突触连接的详细知识。我们已经接近这个问题，通过测量稳态条件下的突触输入，并将它们与定量评估其对猫脊髓运动神经元放电率的影响相结合。2.我们采用改良的电压钳技术，测量猫小腿三头肌运动神经元红核脊髓输入产生的稳态有效突触电流（IN）。在相同的运动神经元中，我们测量了初级范围内的放电频率-注入电流（f-i）关系的斜率。然后，我们重新激活红核脊髓输入稳定，重复发射，以评估其对运动神经元放电率的影响。3.我们发现，由这种突触输入产生的运动神经元稳态放电率的变化可以简单地描述为在索马测量的净有效突触电流和运动神经元的f-i关系的斜率的乘积。这个表达基本上重新定义了突触效能的一个细胞的基本输入输出功能。此外，有效突触电流的测量简化了估计突触功效的任务，因为既不需要突触后细胞的电紧张结构也不需要突触前终扣的位置的详细知识。
1. The basic question of how motoneurons transform synaptic inputs into spike train outputs remains unresolved, despite detailed knowledge of their morphology, electrophysiology, and synaptic connectivity. We have approached this problem by making measurements of a synaptic input under steady-state conditions and combining them with quantitative assessments of their effects on the discharge rates of cat spinal motoneurons. 2. We used a modified voltage-clamp technique to measure the steady-state effective synaptic currents (IN) produced by rubrospinal input to cat triceps surae motoneurons. In the same motoneurons we measured the slope of the firing rate-injected current (f-i) relation in the primary range. We then reactivated the rubrospinal input during steady, repetitive firing to assess its effect on motoneuron discharge rate. 3. We found that changes in the steady-state discharge rate of a motoneuron produced by this synaptic input could be described simply as the product of the net effective synaptic current measured at the soma and the slope of the motoneuron's f-i relation. This expression essentially redefines synaptic efficacy in terms of a cell's basic input-output function. Further, measurements of effective synaptic current simplify the task of estimating synaptic efficacy, because detailed knowledge of neither the electrotonic architecture of the postsynaptic cell nor of the locations of the presynaptic boutons is required.