title: Why decussate? Topological constraints on 3D wiring.
abstract: Many vertebrate motor and sensory systems "decussate" or cross the midline to the opposite side of the body. The successful crossing of millions of axons during development requires a complex of tightly controlled regulatory processes. Because these processes have evolved in many distinct systems and organisms, it seems reasonable to presume that decussation confers a significant functional advantage--yet if this is so, the nature of this advantage is not understood. In this article, we examine constraints imposed by topology on the ways that a three-dimensional processor and environment can be wired together in a continuous, somatotopic, way. We show that as the number of wiring connections grows, decussated arrangements become overwhelmingly more robust against wiring errors than seemingly simpler same-sided wiring schemes. These results provide a predictive approach for understanding how 3D networks must be wired if they are to be robust, and therefore have implications both for future large-scale computational networks and for complex biomedical devices.
authors.affiliation: Department of Biomedical Engineering, Rutgers University, Piscataway, New Jersey 08854, USA. shinbrot@srutgers.edu
authors.forename: Troy
authors.initials: T
authors.lastname: Shinbrot
authors.forename: Wise
authors.initials: W
authors.lastname: Young
mesh_terms: D000465:Algorithms; D000818:Animals; D001698:Biomedical Engineering; D002490:Central Nervous System / Q000033:anatomy & histology; D006801:Humans; D008959:Models, Neurological; D009415:Nerve Net / Q000033:anatomy & histology*; D016571:Neural Networks, Computer