Inhibition Increases Modularity in Bursting Neuronal Networks
MetadataShow full item record
Neuronal networks in dissociated cultures spontaneously generate synchronous activity known as network bursting, which is characterized by the firing of nearly all neurons every 30−100 seconds. There has been much research directed toward understanding the initiation of bursts, as well as the role of underlying network topology. Research has also focused on determining the role of excitatory and inhibitory connections in synchronous bursting behavior; however, it is still unclear how these connections determine network properties. Removing inhibitory connections with bicuculline, a GABAA receptor antagonist, decreases bursting frequency. Theoretical modelling has shown that frequency changes are due to changes in network properties, such as modularity and clustering coefficient. This experiment had the following aims: 1) investigate the effects that inhibitory connections have on modularity and clustering coefficient 2) compare our experimental results with theoretical findings. We observed that with the addition of bicuculline, fluorescence amplitudes increased while bursting frequency decreased. Analysis of connectivity maps revealed that the modularity coefficient decreased by 6% , and the clustering coefficient increased by 3%. Finally, we synthesized results from 5 experiments and concluded that addition of bicuculline increases the weight of the links, average k-degree and clustering coefficient and decreases network modularity. Our experimental findings are consistent with the theoretical framework in the literature, suggesting that synchronous bursting behavior depends on the connectivity of the network.
Department of Physics
File access restricted due to FERPA regulations