Fig. 6.

The bifurcation behaviour, V as functions of $I_m$ and period of the stable periodic orbit. Left: the bifurcation behaviour of a single uncoupled neuron ($N=1$, $g_{\mathrm{syn}}=0$). Top left: voltage V at a fixed point (solid, stable; dashed, unstable) and the maximum and minimum of V over one period of oscillation (circles), as a function of $I_m$. Bottom left: period of the stable periodic orbit for a single uncoupled neuron. The apparent discontinuity in the periodic orbit towards low $I_m$ is because of the canard nature of the oscillations (mentioned in the text). Right: the bifurcation behaviour of a single self-coupled neuron ($N=1$, $g_{\mathrm{syn}}=0.3$). Top right: voltage V at a fixed point (solid stable, dashed unstable) and the maximum and minimum of V over one period of oscillation (circles), as a function of $I_m$. Bottom right: period of the stable periodic orbit for a single self-coupled neuron.