Dear MEA-Users, We are pleased to announce the first public release of MeaBench, an open-source suite of programs for acquisition and analysis of multi-electrode array (MEA) recordings. MeaBench was developed by Daniel Wagenaar at Caltech, drawing on the excellent example set by MultiChannel Systems' MC_Rack suite (www.multichannelsystems.com). The software runs under Linux and other Unix variants, and is freely distributable under the terms of the GNU Public License (see http://www.gnu.org/copyleft/gpl.html). It offers the following functionality: - Acquisition of raw electrode data from MultiChannel Systems' MCCard; - Complete removal of mains (60 Hz) interference using template filtering; - Removal of stimulation artifacts using the SALPA algorithm [1]; - Online and offline detection of spikes; - Online visualization of electrode data and spikes; - Continuous or windowed saving of raw data and spikes; - Saving of spike waveforms, for later spike sorting and analysis; - Replaying of raw and spike files, at any speed; - Instant-replay buffer for easy analysis of recent events; - Online generation of raster plots; - Continuous monitoring of varying noise levels; - A variety of utilities for analysis and data format conversion, including: * Averaging of electrode recordings over trials; * Conversion of binary spike files to ASCII representation; * Filtering of spike files based on any mathematical expression involving shape or timing parameters; * Extraction of single channels from 64 channel streams; * Splitting of long data files into trials; * Splitting of long data files into channels; * Computing spike rates; * Detecting culture-wide bursts. - A selection of Matlab functions to import MeaBench data is available upon request. Users may also be interested in Uli Egert's comprehensive set of matlab code for MEA data analysis, available for download from http://www.brainworks.uni-freiburg.de/projects/mea/meatools/overview.htm MeaBench is fully modular, and any user with some Unix programming experience can extend it to fit her or his needs. Since MeaBench can stream live data to your extension modules, it is well suited, for example, to drive real-time feedback systems. In fact, the ability to communicate with other software or hardware in real-time was one of the primary motives for the conception of MeaBench. It allowed a reliable, sub-100 ms feedback loop time in our Neurally Controlled Animat. [2] MeaBench was written primarily for use with the MultiChannel Systems MEA hardware, and a driver is included for their MCCard data acquisition card, written by Thomas B. DeMarse with advice from MultiChannelSystems. If you use different data acquisition hardware, you may still find MeaBench useful, because, due to its modular nature, it is possible to write plug-in modules to read data from your hardware. An experimental driver for one such board (manufactured by United Electronic Industries, but not endorsed by us at its current state of development) is included as well. MeaBench has been in constant use by my group in the Pine lab at Caltech for over two years, and now also by everyone in my group at Georgia Tech (http://www.its.caltech.edu/~pinelab/PotterGroup.htm). Daniel has worked countless hours creating and improving this very functional set of tools. It remains a work in progress; we welcome suggestions for improvement (and bug reports). Please join in the development by submitting your code (patches and improvements) for inclusion in future releases. Daniel wishes to acknowledge valuable input and support from Tom DeMarse, Jerry Pine, and myself. We are all grateful for financial support from the NIH-NINDS and The Burroughs-Wellcome Fund, and cooperation, technical support, and equipment from MultiChannel Systems. For more information and to download MeaBench, please visit: http://www.its.caltech.edu/~wagenaar/meabench With much enthusiasm for the future of MEAs, Steve M. Potter, PhD Assistant Professor of Biomedical Engineering Neuroengineering Laboratory Coulter Department of Biomedical Engineering Georgia Institute of Technology and Emory University http://www.neuro.gatech.edu/potter.php steve.potter@bme.gatech.edu References: [1] D A Wagenaar, and S M Potter: Real-time multi-channel stimulus artifact suppression by local curve fitting. J. Neurosci. Meth, vol 120 issue 2, 2002 (in press). Preprint available at: www.its.caltech.edu/~wagenaar/salpa-preprint.pdf [2] T B DeMarse, D A Wagenaar, A W Blau, and S M Potter: The neurally controlled animat: biological brains acting with simulated bodies. Autonomous Robots 11, 2001, pp 305-310.