Effective extra-cellular recording from vertebrate neurons in culture using a new type of micro-electrode array

We describe the fabrication and use of a new type of extracellular micro-electrode array mounted on a flexible transparent polyimide substrate that can be rapidly moved from one part of a culture of vertebrate neurons (rat nodose) to another, which permits co-culture of glia under the neurons and is easily and rapidly replaceable in the event of damage. The array can be mounted on a micromanipulator and moved into place whenever and wherever recordings with or without stimulation are needed. The basic electrode system consists of 20-30 microm diameter gold electrodes, with or without platinisation, exposed to the cells through openings in the polyimide and joined to the recording or stimulating circuitry through gold tracks embedded in the polyimide. If rigid control over neuron placement has been achieved the patterns of electrodes can be matched to the neuron positions.