Neocortical-like organization of avian auditory 'cortex'. Commentary on Wang Y, Brzozowska-Prechtl A, Karten HJ (2010): Laminar and columnar auditory cortex in avian brain. Proc Natl Acad Sci USA 107:12676-12681.

摘要

The recent paper by Wang et al. [2010] is noteworthy in that it constitutes the first detailed anatomical evidence bearing on an influential proposal made by Karten over 40 years ago [Karten, 1969; Karten and Shimizu, 1989; Karten, 1991; Shimizu and Karten, 1991; Karten, 1997] regarding the organization and phylogeny of the avi-an telencephalon. In essence, that proposal suggested that large parts of the avian pal-lial telencephalon, namely the sagittal elevation (Wulst) and the dorsal ventricular ridge (DVR), are made up of collections of what are apparently non-laminated clusters of neurons that, nevertheless, correspond in their function and connections with identifiable populations of neocorti-cal neurons in mammals; the defining characteristics of neocortex, of course, being the presence of six neuronal layers possessing a radial organization of functional columns, dependent on their specific in-terlaminar connectivity. Birds and reptiles do not possess a neocortex in this sense, i.e. nowhere in the sauropsid pallium is there evidence of a hexalaminated structure comparable with the neocortex of mammals, although the Wulst and some parts of the DVR are clearly layered in the sense that there are stacked bands of neurons (although considerably wider than neocortical layers) having characteristic size, morphology, packing density and gene expression, for example, and are separated from each other by narrower, fi- brous bands.