An Electro-optical Connectome Prototype for Eight Neuron Representations in FPGA Technology

In nature, interneural signaling is highly parallel and temporally precisely structured. It would require equal parallelism and temporal accuracy to faithfully mimic neural communication in hardware representations. Light-based communication schemes fulfil this prerequisite. We report on a prototype of an optical connectome implementation for a neuromorphic system eventually consisting of eight neurons. The platform is based on field-programmable gate arrays (FPGAs) that run neuron-specific response models. Their axons are represented by light-emitting diodes (LEDs) with axonal arbors in the form of micropatterned transparencies. They distribute membrane voltage threshold crossings, which are represented by light pulses, onto synapse-specific photodiodes of postsynaptic neurons. This contribution sketches out the overall system design and discusses its prospective application in replicating the connectome of the nematode C. elegans in the framework of the Si elegans project.