Dependence of propagation on oscillation amplitude. A, Membrane potential and spiking responses of a prototypic GPe neuron stimulated at 2 Hz and 16 pA. B, The same, but with an 80 pA oscillation. C, The same neuron, stimulated at 80 Hz and 16 pA. D, Stimulation at 80 Hz and 80 pA. Red represents stimulus currents. E, F, Spectra of synaptic current for 80 Hz oscillation at the two stimulus amplitudes. The cell’s intrinsic frequency (42 spikes/s) is reflected in a broad peak in the spectrum of the barrage. G, Magnitude of the stimulus-frequency spectral peak for an example GPe neuron at each of 8 frequencies, for stimulus intensities from 8 to 80 pA. H, Average spectral peak current for the sample of 8 GPe neurons at 5 stimulus frequencies and 10 amplitudes.