Format

Send to

Choose Destination
Cereb Cortex. 2015 Jan;25(1):147-60. doi: 10.1093/cercor/bht214. Epub 2013 Aug 19.

Systematic, cross-cortex variation in neuron numbers in rodents and primates.

Author information

1
Behavioral and Evolutionary Neuroscience Group, Department of Psychology and.
2
Center for Applied Mathematics, Cornell University, Ithaca, NY 14853, USA.

Abstract

Uniformity, local variability, and systematic variation in neuron numbers per unit of cortical surface area across species and cortical areas have been claimed to characterize the isocortex. Resolving these claims has been difficult, because species, techniques, and cortical areas vary across studies. We present a stereological assessment of neuron numbers in layers II-IV and V-VI per unit of cortical surface area across the isocortex in rodents (hamster, Mesocricetus auratus; agouti, Dasyprocta azarae; paca, Cuniculus paca) and primates (owl monkey, Aotus trivigratus; tamarin, Saguinus midas; capuchin, Cebus apella); these chosen to vary systematically in cortical size. The contributions of species, cortical areas, and techniques (stereology, "isotropic fractionator") to neuron estimates were assessed. Neurons per unit of cortical surface area increase across the rostro-caudal (RC) axis in primates (varying by a factor of 1.64-2.13 across the rostral and caudal poles) but less in rodents (varying by a factor of 1.15-1.54). Layer II-IV neurons account for most of this variation. When integrated into the context of species variation, and this RC gradient in neuron numbers, conflicts between studies can be accounted for. The RC variation in isocortical neurons in adulthood mirrors the gradients in neurogenesis duration in development.

KEYWORDS:

cortex; development; gradient; numbers

PMID:
23960207
PMCID:
PMC4259279
DOI:
10.1093/cercor/bht214
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center