Large-scale neural recordings with single neuron resolution using Neuropixels probes in human cortex

Recent advances in multi-electrode array technology have made it possible
to monitor large neuronal ensembles at cellular resolution in animal
models. In humans, however, current approaches restrict recordings to few
neurons per penetrating electrode or combine the signals of thousands of
neurons in local field potential (LFP) recordings. Here, we describe a new
probe variant and set of techniques which enable simultaneous recording
from over 200 well-isolated cortical single units in human participants
during intraoperative neurosurgical procedures using silicon Neuropixels
probes. We characterized a diversity of extracellular waveforms with eight
separable single unit classes, with differing firing rates, locations
along the length of the electrode array, waveform spatial spread, and
modulation by LFP events such as inter-ictal discharges and burst
suppression. While some challenges remain in creating a turn-key recording
system, high-density silicon arrays provide a path for studying
human-specific cognitive processes and their dysfunction at unprecedented
spatiotemporal resolution.