Identifying firing mammalian neurons in networks with high-resolution multi-transistor array (MTA)

The electrical activity of a network of mammalian neurons is mapped with a Multi-Transistor Array (MTA) fabricated with extended CMOS technology. The spatial resolution is 7.4 mu m on an area of 1 mm(2) at a sampling frequency of 6 kHz for a complete readout of 16,384 sensor transistors. Action potentials give rise to extracellular voltages with amplitudes in a range of 500 mu V. On the basis of the high resolution in space and time, correlation algorithms are used to identify single action potentials with amplitudes as low as about 200 mu V, and to assign the signals to the activity of individual neurons even in a dense network.