C. elegans connectome

Each point in the graph represents a neuron. White nodes represent sensory neurons, gray nodes represent interneurons, and black nodes represent motorneurons. Each line represents a connection between two neurons. Blue lines represent chemical synapses. Red lines represent electrical gap junctions. The width of the connection represents the number of synaptic contacts.

This version of the connectome includes again the neuromuscular junctions, represented as green lines. The issue with showing these is that the network focuses only on the neurons, yet the neuromuscular junctions go from neurons to muscles. The connectome database doesn’t contain the muscles individually; instead it clusters them all as one. So in the figure all of the green connections go to one node (green), which represents all muscles.

Also, there’s no directionality represented in the connections for simplicity. That is, connections don’t have arrows. In principle, the chemical synapses should have arrows because chemical synapses are directional - but this makes the image much messier.

The code to produce the network is written in Mathematica. The neural connectivity data available online.