Low frequency firing is modeled by Type 1 neurons with a SNIC, but, because of the vertical slope of the square-root-like f–I curve, low f only occurs over a narrow range of I. When an adaptive current is added, however, the f–I curve is linearized, and low f occurs robustly over a large I range. Ermentrout (Neural Comput. 10(7):1721-1729, 1998) showed that this feature of adaptation paradoxically arises from the SNIC that is responsible for the vertical slope. We show, using a simplified Hindmarsh–Rose neuron with negative feedback acting directly on the adaptation current, that whereas a SNIC contributes to linearization, in practice linearization over a large interval may require strong adaptation strength. We also find that a type 2 neuron with threshold generated by a Hopf bifurcation can also show linearization if adaptation strength is strong. Thus, a SNIC is not necessary. More fundamental than a SNIC is stretching the steep region near threshold, which stems from sufficiently strong adaptation, though a SNIC contributes if present. In a more realistic conductance-based model, Morris–Lecar, with negative feedback acting on the adaptation conductance, an additional assumption that the driving force of the adaptation current is independent of I is needed. If this holds, strong adaptive conductance is both necessary and sufficient for linearization of f–I curves of type 2 f–I curves.

中文翻译：

---

适应如何使低射速稳健。

低频触发是由具有SNIC的1型神经元建模的，但是由于平方根的f–I曲线的垂直斜率，低f仅在I的狭窄范围内发生。当添加自适应电流时，然而，f–I曲线是线性的，并且低f在较大的I范围内稳健地发生。Ermentrout（Neural Comput。10（7）：1721-1729，1998）表明，这种适应性特征自相矛盾地源自负责垂直斜率的SNIC。我们显示，使用具有负反馈直接作用于适应电流的简化欣德马什-罗斯神经元，虽然SNIC有助于线性化，但实际上在较大的时间间隔内线性化可能需要强大的适应强度。我们还发现，如果适应力强，则具有由Hopf分叉产生的阈值的2型神经元也可以显示线性化。因此，不需要SNIC。比SNIC更基本的是将陡峭区域扩展到接近阈值，这是由于足够强的适应性引起的，尽管SNIC会在存在时做出贡献。在一个更现实的基于电导的模型Morris-Lecar中，负反馈作用于自适应电导，还需要一个额外的假设，即自适应电流的驱动力与I无关。如果这样成立，则对于2型f–I曲线的f–I曲线进行线性化，既有必要又要有足够的自适应电导。尽管有SNIC也会提供帮助。在一个更现实的基于电导的模型Morris-Lecar中，负反馈作用于自适应电导，还需要一个额外的假设，即自适应电流的驱动力与I无关。如果这样成立，则对于2型f–I曲线的f–I曲线进行线性化，既有必要又要有足够的自适应电导。尽管有SNIC也会提供帮助。在一个更现实的基于电导的模型Morris-Lecar中，负反馈作用于自适应电导，还需要一个额外的假设，即自适应电流的驱动力与I无关。如果这样成立，则对于2型f–I曲线的f–I曲线进行线性化，既有必要又要有足够的自适应电导。