Figure 1.

Illustration of potential hypotheses of HGA generation. a, HGA recorded by an electrode (vertical triangle) predominantly originates from spectral leakage of summed nearby spikes through volume conduction. b, Recorded HGA predominantly reflects summed postsynaptic potentials (PSPs) that are triggered by spiking activity across the network that trigger PSPs near the recording electrode. Red traces are spike trains, at or near the axon hillock. Green traces are PSPs in dendrites and cell bodies. Purple neurites represent incoming axons from more distantly located neurons.