Projet ANR-MUSIC (2010-2013)

Most breakthroughs in our understanding of the basic mechanisms of information processing in the brain have been obtained with local field potentials (LFPs) and single neuron recordings in freely moving animals. Up until now these recordings have been performed with silicon probes and/or tetrodes, which capture the electrical fields generated by the flux of ions through ion channels localized in the cell membrane. The technology of silicon probes or tetrodes suffers from several limitations, which slow down the process of furthering our understanding of brain function. A technological breakthrough is now necessary, to drive the field to another level of possibilities. In particular, it is crucial to design multimodal technologies facilitating the harvesting of a maximum of the different signatures of network activity, and to decrease the invasiveness of the recording devices. The purpose of MUSIC is to develop a new generation of chronically implantable biocompatible probes displaying multi-sensing recording sites. MUSIC will make use of the most recent technology to address these issues: It will use organic electrochemical transistors which have recently been demonstrated as highly sensitive ion-to-electron converters. As such, they can measure ionic currents through ion channels with high fidelity, enabling a new mode of probing brain function. Moreover, these devices can be functionalized by appropriate biorecognition elements to yield biosensors for a variety of analytes, including metabolites such as glucose. MUSIC will make available an advanced biomedical tool that will have a major impact on neuroscience research. In this sense, it is not purely a technological project. The Inserm partner is interested in information processing in temporal lobe structures during spatial memory tasks in physiological and pathological (epilepsy) conditions. Epilepsy is the second neuronal disorder after migraine; it affects 1-2% of the population worldwide. The Inserm partner already uses the technology described above, i.e. silicon probes and tetrodes. In epilepsy, the limitations of these techniques become very important. The design of these new probes will allow for the first time to investigate the relationship between energy utilization and electrical activity in situ at the microscopic scale in physiological and pathological conditions. MUSIC brings together three partners who are at the forefront of their respective fields: The team at Ecole des Mines de Saint Etienne, with expertise in organic electronics and microfabrication, the epilepsy group of INSERM UMR 751, which will validate the probes and use them for leading research in epilepsy, and Microvitae Technologies, with expertise in design and fabrication of wireless electrophysiological data acquisition systems and commercialization of biomedical technologies.