A 19-channel matrix drive with individually controllable fiber microelectrodes for neurophysiological applications

An electrode matrix manipulator for independent positioning of up to 19 microelectrodes for the recording of electrical activity of a multitude of single units within a neural population is described. It is operated by the combined action of a stepping motor and a system of independently controllable solenoid-operated coupling elements for each electrode. Glass-metal fiber electrodes of 100-μm outside diameter travel in parallel capillary guide tubes, arranged in concentric array with a 220-μm interelectrode distance. Electrode movement is in steps of 2 μm. Simultaneous movement of any combination of electrodes is possible.