Neural Network of C. elegans is a Small-World Network
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Transcript of Neural Network of C. elegans is a Small-World Network
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Neural Network of C. elegans is a Small-World Network
Masroor HossainWednesday, February 29th, 2012Introduction to Complex Systems
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Background on C. elegans
• It’s a transparent nematode (roundworm).• The hermaphrodite version has a simple
nervous system comprising about 302 neurons.
• It’s neural network is completely mapped.• The pattern of connectivity portrays small-
world network characteristics.
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Recall
• The characteristic path length L is defined as the number of edges in the shortest path between two vertices, averaged over all pairs of vertices.
• The clustering coefficient C measures the degree to which nodes in a graph tend to cluster together - how close neighbors are to being a clique.
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Procedure for Measuring C – from class
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Random Rewiring Procedure• p = 0 represents regularity (no edge)• p = 1 represents disorder (clique)• n = 20 and k = 4
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Random Rewiring Procedure
• For C. elegans, an edge/link joins two neurons if they are connected by a synapse or gap junction.
• There are n = 282 nodes and k = 14 edges.
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NetLogo Models
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Cumulative Distribution of Outgoing and Incoming Neural Connections
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Questions?