Fig. 5.

Short-term depression reduces correlations between population conductances. Correlation coefficient between the two excitatory population spike counts (A), between two inhibitory population spike counts (B), and between the excitatory and inhibitory population spike counts as a function of window size (C). D–F: Pearson correlation between the population excitatory and inhibitory conductances produced by the spike trains from A–C using a static, nondepressing synapse model. G–I: Pearson correlation between the synaptic conductances by the spike trains in A–C using a depressing synapse model. Presynaptic excitatory correlations are larger than presynaptic inhibitory correlations at the population level because the excitatory population is larger (see methods). Results from Monte Carlo simulations are plotted along with those obtained from the analytical expressions in methods, but the two are virtually indistinguishable.