Article

Morphological characterization of in vitro neuronal networks

School of Physics and Astronomy, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel-Aviv University, Tel-Aviv 69978, Israel.
Physical Review E (Impact Factor: 2.33). 09/2002; 66(2 Pt 1):021905. DOI: 10.1103/PhysRevE.66.021905
Source: PubMed

ABSTRACT We use in vitro neuronal networks as a model system for studying self-organization processes in the nervous system. We follow the neuronal growth process, from isolated neurons to fully connected two-dimensional networks. The mature networks are mapped into connected graphs and their morphological characteristics are measured. The distributions of segment lengths, node connectivity, and path length between nodes, and the clustering coefficient of the networks are used to characterize network morphology and to demonstrate that our networks fall into the category of small-world networks.

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Available from: Orit Shefi, Oct 04, 2014
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    • "In the case of the brain, different kinds of distribution have been reported depending on the spatial scale at which the system is analyzed, since the scale determines the number of nodes N and links L of the network which, in turn, constrains the width of the degree distribution. In cultured neural networks, the fact that neurons primarily connect through a random process leads to exponential distributions (Shefi et al. 2002). This kind of distribution is also reported in the in-degree and the out-degree of the anatomical connections of C. elegans nematode, the only living system with a whole reconstruction of its neural network (Amaral et al. 2000). "
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    • "Furthermore the clustering coefficient C is very high as in regular networks (C = 1) and contrary to random networks. For the Apollonian network C has been found to be equal to 0.828 in the limit of large N. On this basis, the Apollonian network appears to have all the new features that we would like to investigate: small-world property found experimentally (Shefi et al., 2002) and possibility of a very high connectivity degree (scale-free). Moreover it also presents sites connecting bonds of all lengths. "
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    • "Additional analysis of our datasets, addressing the small-world property of the link distribution based on the ratio of high local clustering and short path length (Humphries & Gurney, 2008; Rubinov & Sporns, 2010), demonstrated that in only a fraction of our experiments did the links underlying repetitive spike pattern revealed small-world properties. Thus, despite the description of small-world properties in morphology and functional synaptic connections in more mature cultures (Shefi et al., 2002; Bettencourt et al., 2007), our results do not provide convincing evidence that a scale-free small-world network underlies repetitive spike patterns at early stages of development in vitro. "
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