Manuel Schottdorf, Nonlinear Dynamics Groups, Max Planck Institute for Dynamics and Self-Organization, Göttingen | Key-innovations in the circuit design of visual cortex

Abstract

The network structure of neuronal circuits determines their function as information-processing devices analyzing sensory information and generating behavior. In mammals, neocortical circuits have been (re-)shaped by evolution during the past 205 million years by two key innovations in forebrain architecture: With the emergence of mammals from mammal-like reptiles the forebrain mantle was transformed to modern neocortex and acquired a topographic and “modular” input organization.

With the rise of modern mammals after the KPg extinction of non-avian dinosaurs, neocortex expanded strongly in many mammalian lineages and e.g. in the visual cortex transformed anatomical cortical columns into functional modules. A paradigmatic example are functional orientation columns in the visual cortex. Systems of functional orientation columns connected through long-range intra-cortical circuits evolved independently in several lineages and converged to a unique design characterized by indistinguishable and quantitatively precise layout laws.

How did these evolutionary transitions in brain circuit design unfold? How strong was the selective pressure that drove them? What are the functional advantages of a columnar organization of neocortical circuits? In my talk, I will show how a combination of mathematical theory and in vitro synthetic neural circuit experiments can shed a new light on these key questions in brain evolution.