Changes in propagation delays for quantifying pharmacological effects on cortical cultures

Multielectrode arrays (MEAs) can be used to capture electrophysiological activity of neuronal cultures with high spatio-temporal resolution and have been successfully employed in detecting changes in activity in the presence of pharmacological additions. One of the key network dynamics of these cultures is spontaneous bursting that spans across the entire network and holds rich information content. In this work, we propose the use of normalized channel-wise propagation delays during such burst events for assessing the effect of pharmacological additions. Furthermore, we investigate multiple metrics based on propagation delays and show that they effectively identify changes induced by an analgesic (a substance with pain relieving properties). Our results show that the change in the proposed metrics induced by the analgesic is significantly more pronounced (p = 0.003-0.0147) than the change induced by control perturbations.