State of the Art
Where the project started: The BioMEA™ System
The BioMEA™ System was developed in the framework of the French ANR project NEUROCOM in order to address one important issue in neurosciences, which is the ability to simultaneously record activities of a large number of cells in long neural network, and to dynamically stimulate the network to control its activity. The goal of the project NEUROCOM was to develop a high-density MEA biochip and the electronics system to record and to stimulate large and living neural networks in vitro of the neural central system. Started in 2004, the project delivered end of 2007 several BioMEA™ System prototypes.
To overcome the limitation of discrete electronics when a very high number is needed on a MEA, a dedicated ASIC (Application Specific Integrated Circuit) named AGNES (ASIC for General Neurons Electrical Study) has been developed at CEA-LETI in order to allow simultaneous recording and stimulation on 64 channels. Each channel of this 64-channel CMOS chip is interfaced with neurons via a MicroElectrode Array (MEA) and includes a low noise, variable gain measurement channel. Stimulations are performed using, for each channel, an 8-to-1 analog multiplexer and a voltage-to-current converter allowing uniform current stimulation independently of the electrode impedance.
The BioMEA™ System interfaces 256 electrodes and performs both recording and stimulation capabilities on all electrodes independently. This system uses four 64-Channels ASICs mounted on a mechanical support allowing electrical interconnections between the ASICs and one 256-channel MEA biochip, recording and stimulation electronics capabilities, and a PC running a specific firmware and providing a user interface. The system BioMEA™ was validated on different biological models in vitro, i.e. spine of mouse embryos by CNRS-CNIC (B. Yvert, Bordeaux), culture of hippocampal neurons with partner Capsant Neurotechnologies Ltd., and dissociated cortical neurons to record spikes and local field potentials at partner Ayanda Biosystems SA in collaboration with EPFL Life Science Department, Lausanne, Switzerland.
An industrial transfer of the BioMEA™ System to Bio-Logic SAS has been done successfully. An industrialized version of the BioMEA™ System is commercially available from Bio-Logic SAS and Ayanda Biosystems SA that produces adequate MEA biochips for the BioMEA™ System.
ASIC named AGNES developed at CEA-LETI. It allows recording and stimulation for 64 channels.
BioMEA™ data acquisition system for electrophysiology applications
For more information, see the also the following reference:
R. Guillemaud et al., A multi-channel platform for recording and stimulation of large neuronal structures, IRBM, 30 (2009) 226-233. Download the PDF here.