Electrode pooling can boost the yield of extracellular recordings with switchable silicon probes

Abstract

State-of-the-art silicon probes for electrical recording from neurons have thousands of recording sites. However, due to volume limitations there are typically many fewer wires carrying signals off the probe, which restricts the number of channels that can be recorded simultaneously. To overcome this fundamental constraint, we propose a method called electrode pooling that uses a single wire to serve many recording sites through a set of controllable switches. Here we present the framework behind this method and an experimental strategy to support it. We then demonstrate its feasibility by implementing electrode pooling on the Neuropixels 1.0 electrode array and characterizing its effect on signal and noise. Finally we use simulations to explore the conditions under which electrode pooling saves wires without compromising the content of the recordings. We make recommendations on the design of future devices to take advantage of this strategy.

Silicon probes for electrical recording from neurons usually have fewer wires than recording channels available to carry signals off the probe, which restricts the number of channels that can be recorded simultaneously. The authors propose to pool electrodes, using a single wire to serve many channels through a set of controllable switches.