Figure 9.

Simulation of extracellular potentials from synaptic input oscillations in a passive pyramidal cell population. 200 apical excitatory and 200 perisomatic inhibitory synapses (A) are triggered each 50 ms, with the initiation times for one type (B, C, inhibitory; D, E, excitatory) modulated within a periodic Gaussian probability density function for f = 50–400 Hz in 50 Hz steps with standard deviations σ = 0.2/f, similar to the firing profiles in the rhythmically spiking population simulations. Synapses of the opposing type are activated with a constant probability. Both synapse types have τ_decay = 4 ms (Materials and Methods). B, D, Example V_e traces for the 50, 100, and 200 Hz cases. C, E, Power spectra of V_e in the pyramidal layer potentials. Insets show the peak power values on a log scale for each oscillation frequency with τ_decay of the oscillating synapses varied from 1–7 ms.