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. 2008 Nov 15;99(4):361–370. doi: 10.1007/s00422-008-0259-4

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© The Author(s) 2008

This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution,and reproduction in any medium, provided the original author(s) and source are credited.

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Fig. 2 — Application of the dynamic I–V method to layer-5 pyramidal cells. a The intrinsic membrane current is plotted against the membrane voltage (black symbols). The dynamic I–V curve (red) is clearly seen to comprise a linear component in the subthreshold region followed by a sharp activation in the region of spike initiation. Inset: Examination of the variance of I _ion near the resting potential in the absence (black) or presence (red) of injected current suggest that the majority of the variance comes from intrinsic noise. b The function is plotted here (symbols) together with the EIF model fit (red). Inset: The exponential rise of the spike generating current is shown in a semi-log plot of F(V) with the leak currents subtracted. c Histograms of the EIF model parameters for a sample (N = 12) of pyramidal cells, showing considerable heterogeneity in the response properties of neurons in this population. d The cellular capacitance calculated with our optimization method (see text) is compared to the result of the standard current-pulse protocol, showing a good agreement between the two methods. e Spike-triggered dynamic I–V curves. The I–V curves measured in small time slices after a spike are plotted together with the EIF fit (green) and the pre-spike I–V curve as a reference (red). f Post-spike dynamics of the EIF model parameters (symbols) together with the fits to an exponential model. While conductance and spike threshold could be accurately fitted with a single exponential, the variation in the equilibrium potential E _L required two exponential components for a good fit. The spike width Δ _T did not vary significantly for these cells. g Comparison of the prediction of the rEIF model (green) with experimental data shows good agreement in the subthreshold region and in the prediction of spike times. h Summary of the performance of the rEIF model for the 12 cells investigated. Left: Prediction of the firing rate. Top right: Histogram of the performance measure. Bottom right: Voltage distribution for the rEIF model (green) and the experimental data (black). The figure is adapted from (Badel et al. 2008)

Inline graphic — Application of the dynamic I–V method to layer-5 pyramidal cells. a The intrinsic membrane current is plotted against the membrane voltage (black symbols). The dynamic I–V curve (red) is clearly seen to comprise a linear component in the subthreshold region followed by a sharp activation in the region of spike initiation. Inset: Examination of the variance of I _ion near the resting potential in the absence (black) or presence (red) of injected current suggest that the majority of the variance comes from intrinsic noise. b The function is plotted here (symbols) together with the EIF model fit (red). Inset: The exponential rise of the spike generating current is shown in a semi-log plot of F(V) with the leak currents subtracted. c Histograms of the EIF model parameters for a sample (N = 12) of pyramidal cells, showing considerable heterogeneity in the response properties of neurons in this population. d The cellular capacitance calculated with our optimization method (see text) is compared to the result of the standard current-pulse protocol, showing a good agreement between the two methods. e Spike-triggered dynamic I–V curves. The I–V curves measured in small time slices after a spike are plotted together with the EIF fit (green) and the pre-spike I–V curve as a reference (red). f Post-spike dynamics of the EIF model parameters (symbols) together with the fits to an exponential model. While conductance and spike threshold could be accurately fitted with a single exponential, the variation in the equilibrium potential E _L required two exponential components for a good fit. The spike width Δ _T did not vary significantly for these cells. g Comparison of the prediction of the rEIF model (green) with experimental data shows good agreement in the subthreshold region and in the prediction of spike times. h Summary of the performance of the rEIF model for the 12 cells investigated. Left: Prediction of the firing rate. Top right: Histogram of the performance measure. Bottom right: Voltage distribution for the rEIF model (green) and the experimental data (black). The figure is adapted from (Badel et al. 2008)