In a modern textbook of histology or cell physiology, electron micrographs illustrate the complexity of living matter. As the resolution of electron microscopes improves, more and more details appear. A nerve fiber is usually regarded as a simple structure, yet at high resolution we can recognize a reticulum of fibers named microtubules, microfilaments, and neurofilaments. Moreover, the fibers are regularly interconnected and in the connections are little rings. What is the function of this network? It looks like a microprocessor.