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Brain Struct Funct (2013) 218:157172 DOI 10.1007/s00429-012-0390-9
ORIGINAL ARTICLE
Cytoarchitectonic mapping of the human dorsal extrastriate cortex
Milenko Kujovic Karl Zilles Aleksandar Malikovic
Axel Schleicher Hartmut Mohlberg Claudia Rottschy
Simon B. Eickhoff Katrin Amunts
Received: 23 September 2011 / Accepted: 31 January 2012 / Published online: 22 February 2012 The Author(s) 2012. This article is published with open access at Springerlink.com
Abstract The dorsal visual stream consists of several functionally specialized areas, but most of their cytoarchitectonic correlates have not yet been identied in the human brain. The cortex adjacent to Brodmann area 18/V2 was therefore analyzed in serial sections of ten human postmortem brains using morphometrical and multivariate statistical analyses for the denition of areal borders. Two previously unknown cytoarchitectonic areas (hOc3d, hOc4d) were detected. They occupy the medial and, to a smaller extent, lateral surface of the occipital lobe. The larger area, hOc3d, is located dorso-lateral to area V2 in the region of superior and transverse occipital, as well as parieto-occipital sulci. Area hOc4d was identied rostral to hOc3d; it differed from the latter by larger pyramidal cells in lower layer III, thinner layers V and VI, and a sharp cortex-white-matter borderline. The delineated areas were
superimposed in the anatomical MNI space, and probabilistic maps were calculated. They show a relatively high intersubject variability in volume and position. Based on their location and neighborhood relationship, areas hOc3d and hOc4d are putative anatomical substrates of functionally dened areas V3d and V3a, a hypothesis that can now be tested by comparing probabilistic cytoarchitectonic maps and activation studies of the living human brain.
Keywords Cytoarchitecture Visual cortex hOc3d
hOc4d V3 V3a Probabilistic maps Human brain atlas
Introduction
Functional neuroimaging studies have revealed a complex segregation of the human visual cortex (DeYoe et al. 1996; Malach et al. 1995; Pitzalis et al. 2006; Reppas et al. 1997; Sereno et al. 1995; Tootell et al. 1995a, b; Tootell and Hadjikhani 2001; Watson et al. 1993; Wilms et al. 2005, 2010). A unique area V3, adjoining both the dorsal and the ventral parts of area V2 (BA 18/V2) has been proposed by Zeki (e.g., Zeki 1978, 2003). Other authors distinguished a dorsal (V3 (d)) and a ventral (VP or V3v) subarea of area V3 (van Essen and Drury 1997;...