Deviation from independence of intrinsic currents for adjacent neurons.

<p>A: Deviation from independence of intrinsic currents flowing through the membrane of pairs of adjacent neurons in the GIF network. Shades of red (blue) indicate values that occur more (less) often than what expected under the assumption of independence. C, E: The same as A, but the probability density functions and are conditioned on the peak (C) or trough (E) of the mean oscillation. B, D and F: The same as A, C and E, for the IF network.</p

Parameter descriptions and canonical values used throughout this study, unless otherwise stated.

<p>Parameter descriptions and canonical values used throughout this study, unless otherwise stated.</p

Effects of membrane potential depolarization and coupling on network dynamics.

<p>A: Membrane potential distributions of GIF and r-matched IF neurons in response to the background input alone, for different values of the background inhibition-to-excitation ratio <i>k</i>. In all cases, the voltage threshold for spike generation has been adjusted in order to match the rate response of the canonical GIF (73.7 Hz). Color and line style code as indicated. Inset shows the mean membrane potential as a function of <i>k</i> for the four model networks shown in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003574#pcbi-1003574-g003" target="_blank">Figure 3</a> (same line colors and styles). B, D: Synchrony (as assessed by , B) and firing rates (D) as a function of coupling strength . C: Enlarged view of B for low values of coupling strength. E: Ratio between corresponding curves in C. Solid lines show ratios between canonical models ((GIF)/(IF)), while dashed lines show ratios between models that have been adjusted in order to exhibit the same rate response to the background input (purple, blue and light blue, (GIF)/(r-matched IF); brown, red and orange, (r-matched GIF)/(IF)). Dots in B–E indicate simulated points, lines are drawn to guide the eye.</p

Distribution of intrinsic currents conditioned on the phase of the population rhythm.

<p>Probability density functions of intrinsic currents in the GIF (blue) and IF (red) networks. Solid lines indicate unconditional probability densities, dashed (dotted) lines indicate probability densities conditioned on the peak (trough) of the mean oscillation.</p

Circular-linear correlation analysis corresponding to the data plotted in Figure 9.

<p>Circular-linear correlation analysis corresponding to the data plotted in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1003574#pcbi-1003574-g009" target="_blank">Figure 9</a>.</p

Mean and standard deviation of the membrane potential across neurons.

<p>A: Covariation of the mean membrane potential and the mean intrinsic current across neurons in the GIF (blue) and IF (red) networks. B, C: Bivariate probability density function of the mean and standard deviation of the membrane potential variable across neurons for the GIF (B) and IF (C) networks. Brighter colors indicate higher probabilities.</p

Intrinsic and synaptic currents.

<p>Population rate (A), along with the mean membrane potential <i>v</i> (B), the mean synaptic current (C), and the mean intrinsic current (D) across neurons for the GIF network in a short representative time window. Blue lines show simulation results, black lines are least-squares sinusoidal fits. The red vertical lines indicate the peak of the sinusoidal fit to the corresponding traces, the green vertical line indicates the trough of the sinusoidal fit to the mean membrane potential. Phase leads (, in radians) with respect to the mean membrane potential oscillation are shown for the mean synaptic current and the mean intrinsic current .</p

Single-neuron and network statistics for the IF and GIF models considered.

<p>Single-neuron and network statistics for the IF and GIF models considered.</p

Linear analysis of the neuron models.

<p>Linear analysis of the model neurons with fixed external conductances. A: Resting potential as a function of the background inhibition-to-excitation ratio <i>k</i> for the canonical value of (solid lines), and as a function of the background synaptic excitation for the canonical value of (dashed lines). Solid lines refer to the bottom axis; dashed lines to the top axis. Circles show the canonical values of the corresponding parameters. B: Effective membrane time constant as a function of <i>k</i> and . Line styles, colors and symbols as in A. C: Effective intrinsic frequency as a function of <i>k</i> and . Line styles, colors and symbols as in A. D: IPSPs in response to a single presynaptic pulse delivered at time t = 0, in the presence (dashed lines) or absence (solid lines) of fixed background conductances. Inset shows the membrane potential response to an instantaneous perturbation.</p

Phase relationships of synaptic and intrinsic currents and their effect on synchrony

<p>A: Phase of the sinusoidal fit to the mean synaptic current plotted against the local level of synchrony (as assessed by the amplitude of the sinusoidal fit to the mean membrane potential ). GIF: blue; IF: red. Crosses: canonical models; circles: r-matched models. B: As in A, for the mean intrinsic current . Only GIF networks are shown, as is always equal to in IF networks. C: As in A, for .</p