Spatio-temporal electrical stimuli shape behavior of an embodied cortical network in a goal-directed learning task

• Published in: Journal of neural engineering Vol. 5; no. 3; pp. 310 - 323
• Main Authors: Bakkum, Douglas J, Chao, Zenas C, Potter, Steve M
• Format: Journal Article
• Language: English
• Published: England 01.09.2008
• Subjects: Action Potentials - physiology; Animals; Biomimetics - methods; Cells, Cultured; Cerebral Cortex - physiology; Electric Stimulation - methods; Goals; Learning - physiology; Nerve Net - physiology; Neurons - physiology; Rats; Task Performance and Analysis
• ISSN: 1741-2560
• DOI: 10.1088/1741-2560/5/3/004

We developed an adaptive training algorithm, whereby an in vitro neocortical network learned to modulate its dynamics and achieve pre-determined activity states within tens of minutes through the application of patterned training stimuli using a multi-electrode array. A priori knowledge of functional connectivity was not necessary. Instead, effective training sequences were continuously discovered and refined based on real-time feedback of performance. The short-term neural dynamics in response to training became engraved in the network, requiring progressively fewer training stimuli to achieve successful behavior in a movement task. After 2 h of training, plasticity remained significantly greater than the baseline for 80 min (p-value<0.01). Interestingly, a given sequence of effective training stimuli did not induce significant plasticity (p-value=0.82) or desired behavior, when replayed to the network and no longer contingent on feedback. Our results encourage an in vivo investigation of how targeted multi-site artificial stimulation of the brain, contingent on the activity of the body or even of the brain itself could treat neurological disorders by gradually shaping functional connectivity.