title: Coding principles of the canonical cortical microcircuit in the avian brain.
abstract: Mammalian neocortex is characterized by a layered architecture and a common or "canonical" microcircuit governing information flow among layers. This microcircuit is thought to underlie the computations required for complex behavior. Despite the absence of a six-layered cortex, birds are capable of complex cognition and behavior. In addition, the avian auditory pallium is composed of adjacent information-processing regions with genetically identified neuron types and projections among regions comparable with those found in the neocortex. Here, we show that the avian auditory pallium exhibits the same information-processing principles that define the canonical cortical microcircuit, long thought to have evolved only in mammals. These results suggest that the canonical cortical microcircuit evolved in a common ancestor of mammals and birds and provide a physiological explanation for the evolution of neural processes that give rise to complex behavior in the absence of cortical lamination.
authors.affiliation: Program in Neurobiology and Behavior.
authors.forename: Ana
authors.initials: A
authors.lastname: Calabrese
authors.affiliation: Program in Neurobiology and Behavior, Psychology Department, and Kavli Institute, Columbia University, New York, NY 10027 sw2277@columbia.edu.
authors.forename: Sarah M N
authors.initials: SM
authors.lastname: Woolley
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001717:Birds; D046369:Finches / Q000502:physiology*; D007395:Interneurons / Q000502:physiology; D008297:Male; D009415:Nerve Net / Q000502:physiology*; D009622:Noise
keywords: cortex evolution; functional connectivity; sensory coding; songbird