High-density microelectrode array system and optimal filtering for closed-loop experiments

Emerging CMOS-based microelectrode array devices allow for recording and stimulation of neuronal networks at high spatiotemporal resolution. The assignment of spiking events to individual neurons, a problem referred to as “spike sorting”, is required for the analysis of neuronal recordings. For closed-loop experiments, where a feedback stimulus is applied in response to neuronal spiking patterns, real-time spike sorting techniques are needed. In this paper we demonstrate the potential of using optimal filters in combination with a bidirectional high-density microelectrode array, in order to perform real-time spike sorting also in the presence of overlapping spikes. The high spatial electrode density allows the selection of the electrodes that provide the best filtering performance.