Quadratic Integrate-and-Fire

$$\tau \frac{d}{dt}u=a\mathrm{\_}0(u-u\mathrm{\_}rest)(u-u\mathrm{\_}c)+RI$$

Default parameters: $\tau =10$ ms, $a\mathrm{\_}0=0.1m{V}^{-1}$, $u\mathrm{\_}c=-55$ mV, $u\mathrm{\_}rest=-70$ mV, $R=10M\mathrm{\Omega }$, $I=2.2nA$, firing threshold $u\mathrm{\_}thr=-40mV$.