Figure 6.

Fitting the firing properties of P17–P18 neurons to the Brette-Gerstner neuron model. A, At left are examples of the responses of a control neuron and a VPA neuron to the injection of a 100 pA current step. At right are the responses of model neurons fitted to these recordings. Calibration: vertical, 25 mV; horizontal, 100 ms. B, Left, Average f–I curves of the model neurons (open circles) match those of the real neurons (closed circles). Control averages (n = 16) are in black, VPA averages (n = 16) are in gray. Error bars indicate SEM. Right, Scatter plots of the initial f–I slope (Hz/pA) and rheobase current (pA) for the 32 recordings. In both plots, the horizontal axis indicates measurements taken from real neurons, and the vertical axis indicates measurements taken from model neurons. Black dots are control data, gray dots are VPA data. The data points in the rheobase plot have been jittered (∼5 pA) to make overlapping points easier to distinguish. C, Box plots of the parameters of the Brette-Gerstner model for control (n = 16, black) and VPA (n = 16, gray) neurons. The parameters are capacitance C, leak conductance g_L, leak reversal potential E_L, effective threshold potential V_T, threshold slope factor Δ_T, reset potential V_r, subthreshold adaptation parameter a, spike-triggered adaptation parameter b, and adaptation time constant τ_w. The number at the upper left of each plot indicates the p-value (Bonferroni-corrected t test) of the comparison between the control and VPA means. Only the difference for b is significant.