High-resolution multitransistor array recording of electrical field potentials in cultured brain slices

We report on the recording of electrical activity in cultured hippocampal slices by a multitransistor array (MTA) with 16,384 elements. Time-resolved imaging is achieved with a resolution of 7.8 microm on an area of 1 mm2 at 2 kHz. A read-out of fewer elements allows an enhanced time resolution. Individual transistor signals are caused by local evoked field potentials. They agree with micropipette measurements in amplitude and shape. The spatial continuity of the records provides time-resolved images of evoked field potentials and allows the detection of functional correlations over large distances. As examples, fast propagating waves of presynaptic action potentials are recorded as well as patterns of excitatory postsynaptic potentials across and along cornu ammonis.