Applying a network reconstruction method to reveal connectivity of in-vitro neuronal culture from measurements

We discuss our application of a method for reconstructing directed networks from dynamics [Ching and Tam, Phys. Rev. E 95, 010301(R) (2017)] to reveal the directed links and synaptic weights of in-vitro cortical neuronal cultures from voltage measurements recorded by a multielectrode array. The voltage signal measured by each electrode after noise reduction is treated as the activity x_i(t) of node i, i = 1, 2,..., N, of a neuronal network of N=4095 nodes. The reconstructed connectivity reproduces various reported features of cortical regions in rats and monkeys. The average synaptic strengths of excitatory incoming and outgoing links in the reconstruction are found to increase with the spiking activity recorded in the electrodes. Numerical simulations of a network of spiking neurons using the reconstructed effective connectivity can reproduce such dependence of the network features on firing rates and the long-tailed distribution of firing rate found in the multielectrode recordings. Our results thus support that the reconstructed connectivity can capture the general properties of synaptic connections and reveal relationships between network structure and dynamics of neuronal cultures.