Control of Bursting in Neuronal Ensembles by Closed-loop Control of Tonic Firing Rates
Dynamical Neuroscience XII (“Closing the loop”), satellite at 34th Annual Meeting of the Society for Neuroscience, San Diego, CA, Oct 21–22, 2004
The activity of high-density cortical neuronal ensembles in dissociated culture is dominated by globally synchronized bursts, reminiscent of interictal bursts seen in epileptic patients. A few years ago, Latham et al [1] found that networks with a larger fraction of endogenously active cells have lower propensity to bursting. We asked whether using electrical stimulation to increase the tonic firing rate of neuronal ensembles above their spontaneous activity level could be used to quiet bursting. We combined real-time data acquisition and spike detection software [2] with a real-time controlled stimulator [3] to modulate the firing patterns of neuronal ensembles cultured on multi-electrode arrays. We continuously provided 10 stimuli per second to the culture, distributed across 10 electrodes, and adapted the stimulation voltage in closed-loop feedback to match the response rate to a preset target. By increasing the culture-wide firing rate to about 500 spikes/second (summed from 55 electrodes), we could eliminate bursting in over 50% of cultures tested. We hope that this form of non-pharmacological burst control may have applications for the treatment of epilepsy.
[1] P E Latham, B J Richmond, S Nirenberg, and P G Nelson, 2000. Intrinsic dynamics in neuronal networks. II. Experiment. J. Neurophysiol. 83 pp 828-835.
[2]D A Wagenaar, 2002. Meabench. www.its.caltech.edu/~wagenaar/meabench.html
[3]D A Wagenaar, and S M Potter, 2004. A versatile all-channel stimulator for electrode arrays, with real-time control. J. Neural Eng. 1 pp 39-44.