A NEW EXTRACELLULAR MULTIRECORDING SYSTEM FOR ELECTROPHYSIOLOGICAL STUDIES - APPLICATION TO HIPPOCAMPAL ORGANOTYPIC CULTURES

The present paper describes a new multirecording device which performs continuous electrophysiological studies on organotypic cultures. This device is formed by a card (Physiocard(R)) carrying the culture which is inserted into an electronic module. Electrical activities are reco rded by an array of 30 biocompatible microelectrodes which are adjuste d into close contact with the upper surface of the slice culture. The microelectrode array is integrated into the card enabling electrical s timulation and recording of neurons over periods ranging from several hours to a few days outside a Faraday cage. Neuronal responses are rec orded and analyzed by a dedicated electronic and acquisition chain. A perfusion chamber is contained in the card, allowing continuous perfus ion in sterile conditions. Electrophysiological extracellular recordin gs and some drugs' effects obtained with this system in hippocampal sl ice cultures were identical to conventional electrophysiological set-u p results with tetrodotoxin, bicuculline, kainate, dexamethasone and N BQX. The Physiocard(R) system allows new insights for studies on nervo us tissue and allows sophisticated approaches to be used quicker and m ore easily. It could be used for various neurophysiological studies or screening tests such as neural network mapping, nervous recovery, epi lepsy, neurotoxicity or neuropharmacology. (C) 1997 Elsevier Science B .V.