Figure 4.

Analysis of the population model. A–D, Bifurcation diagrams for the variations of the maximal synaptic conductances, including recurrent excitation $g_{EE}$, excitation from excitatory to inhibitory population $g_{EI}$, inhibition from inhibitory to excitatory population $g_{IE}$, and the recurrent inhibition in the inhibitory population $g_{II}$, respectively. E, F, Bifurcation diagrams for adaptation in the excitatory population $g_{AHP}$ and GABA reversal potential $V_{GABA}$ from the inhibitory-to-excitatory current, $g_{IE}i(U_E-V_{GABA})$. Diagrams A–D were calculated for $g_{IE}$ = 2 mS/cm²; E, g_IE = 0.5 mS/cm²; and F, g_IE 1 mS/cm². The value of $U_E$ characterizes the average membrane potential in the resting state and maximal/minimal values of $U_E$ during the oscillations. Red and green dots correspond to the supercritical and subcritical Andronov–Hopf bifurcations. Solid and dotted lines depict the stable and unstable solutions.