Fig. 5
Effect of z nullcline slope. (A) Decreasing the slope shifts the intersections with the \(\langle x \rangle\) curve. This results in larger steady-state z and lower firing rate. Nullclines drawn for \(s = 2\) (red), \(s = 22\) (green), and \(s = 33\) (blue); \(\langle x \rangle\) drawn for I= 0.18, 3, 6, 9, increasing to the right. (B) \(f(I)\) for the system without adaptation and the three slopes in (A). (C) Least squares linear fits (thin) for the three f–I curves (thick) in (A) over intervals of length 6 starting at the threshold for the corresponding value of s. (D) L2 error for I over intervals of length 6 (lower) and 10 (upper) as a function of s