Stevens C F
Biophys J. 1976 Aug;16(8):891-5. doi: 10.1016/S0006-3495(76)85739-6.
In the limit of slowly varying synaptic conductance changes, a quantity proportional to the quantal content of a synaptic potential is provided by Martin's formula: 1/(VO/Vp-1), where Vp is the peak amplitude of the synaptic potential and Vo is the synaptic equilibrium potential. If the synaptic conductance change is not slowly varying on the time scale of the postsynaptic cell's membrane time constant, Martin's formula overestimates the effects of nonlinear summation and provides an upper limit for the actual quantal content. In the limit of rapidly varying synaptic conductance changes the quantity ln(1/[1-Vp/Vo]) is proportional to the quantal content. This formula underestimates the effects of nonlinear summation and gives a lower limit for the quantal content for cases in which the synaptic conductance is not rapidly varying. These two formulas used together provide upper and lower bounds to the correction for nonlinear summation of postsynaptic potentials.
在突触电导变化缓慢的极限情况下,马丁公式给出了一个与突触电位的量子含量成比例的量:1/(Vo/Vp - 1),其中Vp是突触电位的峰值幅度,Vo是突触平衡电位。如果突触电导变化在突触后细胞膜时间常数的时间尺度上不是缓慢变化的,马丁公式会高估非线性总和的影响,并为实际量子含量提供一个上限。在突触电导变化快速的极限情况下,量ln(1/[1 - Vp/Vo])与量子含量成比例。对于突触电导变化不迅速的情况,该公式低估了非线性总和的影响,并给出了量子含量的下限。这两个公式一起使用为突触后电位非线性总和的校正提供了上限和下限。