A device to make multiple, simultaneous measurements of electrical activity on neural, muscular and other animal cells. The invention discloses multiple electrodes at fixed position on a supporting structure and multiple wires to connect the electrodes to one or more measuring devices. The electrodes are preferentially closed spaced, to allow for small spatial discrimination between measurement points. The electrodes and the wires are selected by binary addresses. The device is also capable of injecting electrical stimulation using electrodes not in use for measurements. An injected electrical stimulation at a first location may be created to measure the effect of a well-known event at another location or locations, near or far away.
