Implementation of Microbe-Based Neurocomputing with Euglena Cells Confined in Micro-Aquariums

Using real Euglena cells in a micro-aquarium as photoreactive biomaterials, we demonstrated Euglena-based neurocomputing with two-dimensional optical feedback using the modified Hopfield–Tank algorithm. The blue light intensity required to evoke the photophobic reactions of Euglena cells was experimentally determined, and the empirically derived autoadjustment of parameters was incorporated in the algorithm. The Euglenabased neurocomputing of 4-city traveling salesman problem possessed two fundamental characteristics: (1) attaining one of the best solutions of the problem and (2) searching for a number of solutions via dynamic transition among the solutions (multi-solution search). The spontaneous reduction in cell number in illuminated areas and the existence of photoinsensitive robust cells are the essential mechanisms responsible for the two characteristics of the Euglena-based neurocomputing