Comparison of Electro-Optical Strategies for Mimicking C. elegans Network Interconnectivity in Hardware

With exactly 302 neurons and about 8000 connections, the hermaphrodite of the soil-dwelling ringworm Caenorhabditis elegans features one of the simplest nervous systems in nature. The Si elegans project will provide a reverse-engineerable model of this nematode by emulating its nervous system and embodying it in a virtual world. The hardware will consist of 302 individual FPGAs, each carrying a neuron-specific neural response model. The FPGA neurons will be interconnected by an electro-optical connectome to distribute the signal at the axonal output or gap-junction pin of an FPGA neuron onto the respective synaptic input or gap-junction pins of postsynaptic FPGA neurons. This technology will replicate the known connectome of the nematode to allow for a biomimetic parallel information flow between neurons. This chapter focuses on the comparison of different electro-optical connectome concepts and on the required implementation steps with their advantages and disadvantages being explained.