title: The Representation of Orientation in Macaque V2: Four Stripes Not Three.
abstract: Area V2 of macaque monkeys is traditionally thought to consist of 3 distinct functional compartments with characteristic cortical connections and functional properties. Orientation selectivity is one property that has frequently been used to distinguish V2 stripes, however, this receptive field property has been found in a high percentage of neurons across V2 compartments. Using quantitative intrinsic cortical imaging, we derived maps of preferred orientation, orientation selectivity, and orientation gradient in thin stripes, thick stripes, and interstripes in area V2. Orientation-selective responses were found in each V2 stripe, but the magnitude and organization of orientation selectivity differed significantly from stripe to stripe. Remarkably, the 2 pale stripes flanking each cytochrome oxidase dense stripe differed significantly in their representation of orientation resulting in their distinction as type-I and type-II interstripes. V2 orientation maps are characterized by clockwise and anticlockwise "orientation pinwheels", but unlike V1, they are not homogeneously distributed across V2. Furthermore, V2 stripes contain large-scale sequences of preferred orientation. These analyses demonstrate that V2 consists of 4 distinct functional compartments; thick stripes and type-II interstripes, which are strongly orientation selective and thin stripes and type-I interstripes, which are significantly less selective for orientation and exhibit larger orientation gradient magnitudes.
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Felleman
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA Department of Computer Science, Prairie View A&M University, Prairie View, TX, USA.
authors.forename: Heejin
authors.initials: H
authors.lastname: Lim
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA Departments of Ophthalmology, Physiology and Pharmacology, and the SUNY Eye Institute, State University of New York Downstate Medical Center, Brooklyn, NY, USA.
authors.forename: Youping
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Eriksson
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Medical School-Houston, Houston, TX 77030, USA.
authors.forename: Arun
authors.initials: A
authors.lastname: Parajuli
mesh_terms: D000818:Animals; D001931:Brain Mapping; D023882:Dominance, Ocular; D003576:Electron Transport Complex IV / Q000378:metabolism; D005260:Female; D049408:Luminescent Agents / Q000378:metabolism; D008163:Luminescent Measurements; D008252:Macaca fascicularis; D008297:Male; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation; D060388:Support Vector Machine; D014793:Visual Cortex / Q000033:anatomy & histology* / Q000378:metabolism / Q000502:physiology*; D014795:Visual Pathways
chemical_list: D049408:Luminescent Agents; D003576:Electron Transport Complex IV
keywords: cortical modules; cortical streams; cytochrome oxidase; intrinsic imaging; visual cortex