Connectivity and plasticity in cultured neuronal networks.

Abstract

Event Abstract Back to Event Connectivity and plasticity in cultured neuronal networks. Joost Le Feber1* 1 University of Twente, Biomedical Signals and Systems, Netherlands To study plasticity, we cultured networks of (rat) cortical neurons on multi electrode arrays, enabling simultaneous recording from multiple neurons. We used Conditional Firing Probabilities (CFPi,j[]; the probability to record an action potential from neuron j at t=, given that i fired at t=0) to describe functional network connections. We fitted a function to the CFP-curve to obtain parameters for ‘strength’ and ‘delay’ (i.e. maximum of the curve, and latency of the maximum). Most functional connections developed rather gradually, typically with coefficient of variation CVstrength≈25% in 10 hour periods. We concluded that CFP analysis provides a robust method to describe the underlying probabilistic structure of highly varying spontaneous activity in cultured cortical networks. However, functional connections are abstract representations of neuronal pathways, and may arise from causal pathways between two neurons, or from a common input. Functional connections based on causal pathways should reflect synaptic properties. Therefore, we searched for long term potentiation (LTP; this mechanism occurs in vivo when presynaptic action potentials precede postsynaptic ones with interspike intervals up to ~20ms) in vitro. To investigate if the strength of functional connections showed a similar latency related development, we selected periods of monotonously increasing or decreasing strength. We observed increased incidence of short latencies (5-30ms) during strengthening, whereas these latencies rarely occurred during weakening. Furthermore, we saw an increased incidence of 40-65ms latencies during weakening. Conversely, functional connections tended to strengthen in periods with short latency, whereas strengthening was significantly less than average during long latency. Our data suggests that functional connections do contain information about synaptic connections, that CFP analysis is sensitive enough to detect it, and that a substantial fraction of all functional connections is based on causal synaptic pathways. We applied CFP analysis to investigate the effects on connectivity of several protocols that were proposed in literature to induce plasticity in cultured networks, including random electrical stimulation, single electrode stimulation and a closed loop protocol aiming to double the responsiveness of a predefined electrode to electrical stimulation. All protocols yielded connectivity changes larger than during similar periods without stimulation. The closed loop protocol showed connectivity changes that were far larger than those seen with the other stimulation protocols. However, the direction of changes remained largely unpredictable. Keywords: functional connectivity, in vitro, neuronal networks Conference: The Monte Verita' Workshop on the Frontiers in Neuroengineering, Ascona, Switzerland, 5 Sep - 9 Sep, 2010. Presentation Type: Oral Presentation Topic: Frontiers in Neuroengineering Citation: Le Feber J (2010). Connectivity and plasticity in cultured neuronal networks.. Front. Neuroeng. Conference Abstract: The Monte Verita' Workshop on the Frontiers in Neuroengineering. doi: 10.3389/conf.fneng.2010.10.00002 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 26 Aug 2010; Published Online: 10 Sep 2010. * Correspondence: Dr. Joost Le Feber, University of Twente, Biomedical Signals and Systems, Enschede, 7500AE, Netherlands, lefeber@udn.fgg.eur.nl Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Joost Le Feber Google Joost Le Feber Google Scholar Joost Le Feber PubMed Joost Le Feber Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.