Spike discrimination using amplitude measurements with a low-power CMOS neural amplifier

Integrated CMOS neural amplifiers have recently grown in importance as large microelectrode arrays have begun to be practical. We previously reported low-power neural amplifiers with integrated pre-filtering and measurements of the spike signal to reduce data bandwidth and to facilitate spike-sorting prior to transmission to a data-acquisition system. Characteristics of a prototype circuit were reported using a 1.5 V power supply, suitable for single cell battery operation. Here we report improved transient amplitude tracking as well as application of the circuit in live recordings of wide-field motion sensitive cells in blowflies. The features extracted by the chip efficiently discriminate between stimulus conditions, as demonstrated by receiver operating characteristic analysis.