Effective connectivity of depth-structure-selective patches in the lateral bank of the macaque intraparietal sulcus

PLoS Biol. 2015 Feb 17;13(2):e1002072. doi: 10.1371/journal.pbio.1002072. eCollection 2015 Feb.

Abstract

Extrastriate cortical areas are frequently composed of subpopulations of neurons encoding specific features or stimuli, such as color, disparity, or faces, and patches of neurons encoding similar stimulus properties are typically embedded in interconnected networks, such as the attention or face-processing network. The goal of the current study was to examine the effective connectivity of subsectors of neurons in the same cortical area with highly similar neuronal response properties. We first recorded single- and multi-unit activity to identify two neuronal patches in the anterior part of the macaque intraparietal sulcus (IPS) showing the same depth structure selectivity and then employed electrical microstimulation during functional magnetic resonance imaging in these patches to determine the effective connectivity of these patches. The two IPS subsectors we identified-with the same neuronal response properties and in some cases separated by only 3 mm-were effectively connected to remarkably distinct cortical networks in both dorsal and ventral stream in three macaques. Conversely, the differences in effective connectivity could account for the known visual-to-motor gradient within the anterior IPS. These results clarify the role of the anterior IPS as a pivotal brain region where dorsal and ventral visual stream interact during object analysis. Thus, in addition to the anatomical connectivity of cortical areas and the properties of individual neurons in these areas, the effective connectivity provides novel key insights into the widespread functional networks that support behavior.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Attention / physiology
  • Brain Mapping
  • Electric Stimulation
  • Electrodes
  • Hand Strength / physiology
  • Macaca mulatta
  • Magnetic Resonance Imaging
  • Male
  • Nerve Net / physiology*
  • Neural Pathways / physiology*
  • Neurons / physiology*
  • Parietal Lobe / anatomy & histology
  • Parietal Lobe / physiology*
  • Photic Stimulation
  • Psychomotor Performance / physiology*
  • Saccades / physiology
  • Stereotaxic Techniques

Grant support

PJ and WV received funding from geconcerteerde onderzoeksacties GOA/10/19; http://www.kuleuven.be/onderzoek/kernprojecten/goa.htm. PJ and WV received funding from interuniversity attraction poles IUAP VII/11; http://www.belspo.be/belspo/fedra/prog.asp?l=nl&COD=p5. PJ and WV received funding from PFV/10/008; WV received funding from National Science Foundation NSF grant BCS-0745436; http://www.nsf.gov/. WV and PJ received funding from Fonds Wetenschappelijk onderzoek FWO grant G.0713.09, G.0622.08, and G.0831.11; http://www.fwo.be/. PJ received funding from European Research Council ERC Stg-260607; http://erc.europa.eu/. PJ and WV received funding from Odysseus grant G.0007.12; http://www.fwo.be/nl/mandaten-financiering/onderzoeksprojecten/odysseusprogramma/. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.