Fig 4. The ratio of the width to the center of the distribution of currents Eq (14), δ = Δ/Θ, determines the presence of fast oscillations in the QIF-FRE.

Oscillations disappear above the critical value given by Eq (8). The panels show the Hopf boundaries of QIF-FRE with first-order synapses, for different values of δ, obtained solving the characteristic Eq (6) with Re(λ) = 0, see Materials and methods. Shaded regions are regions of oscillations. Symbols in the right panel correspond to the parameters used in Fig 3.