FIG. 3.

Resonate-and-fire model. Voltage dependence of subthreshold model parameters, as obtained from physiological data. The 4 rows represent the four parameters (C, /2π, γ/C, D), shown for 4 stellate and 4 pyramidal cells (left and right columns, respectively). Different colors correspond to different neurons; the 2 cells presented in Fig. 1 are marked in black. A and B: capacity C, derived from fitting the experimental impedance function with the theoretical curve obtained from the resonate-and-fire model. C and D: eigenfrequency /2π, obtained from fitting the experimental impedance and autocorrelation functions with the model. E and F: damping coefficient γ/C, calculated from the experimental impedance and autocorrelation functions. G and H: noise intensity D, obtained from the experimental autocorrelation function. As shown by these data, the noise intensity D strongly depends on the level of membrane depolarization in both cell classes. In addition, in stellate cells the damping coefficient γ/C decreases rapidly with increasing membrane depolarization.