Organization of the human inferior parietal lobule based on receptor architectonics

Cereb Cortex. 2013 Mar;23(3):615-28. doi: 10.1093/cercor/bhs048. Epub 2012 Feb 28.

Abstract

Human inferior parietal lobule (IPL) plays a key role in various cognitive functions. Its functional diversity, including attention, language, and action processing, is reflected by its structural segregation into 7 cytoarchitectonically distinct areas, each with characteristic connectivity patterns. We hypothesized that commonalities of the cytoarchitectonic, connectional, and functional diversity of the IPL should be reflected by a correlated transmitter receptor-based organization. Since the function of a cortical area requires a well-tuned receptor balance, the densities of 15 different receptors were measured in each IPL area. A hierarchical cluster analysis of the receptor balance revealed a tripartite segregation of the IPL into a rostral, middle, and caudal group. Comparison with other cortical areas showed strong similarities with Broca's region for all 3 groups, with the superior parietal cortex for the middle, and with extrastriate visual areas for the caudal group. Notably, caudal-most area PGp has a receptor fingerprint very similar to that of ventral extrastriate visual cortex. We therefore propose a new organizational model of the human IPL, consisting of 3 clusters, which corresponds to its known cytoarchitectonic, connectional, and functional diversity at the molecular level. This might reflect a general organizational principle of human IPL, beyond specific functional domains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Autoradiography
  • Brain Mapping*
  • Cluster Analysis
  • Female
  • Humans
  • Male
  • Parietal Lobe / metabolism*
  • Receptors, Neurotransmitter / analysis*
  • Receptors, Neurotransmitter / biosynthesis*

Substances

  • Receptors, Neurotransmitter