Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 2016 Aug 23;113(34):9617-22. doi: 10.1073/pnas.1610178113. Epub 2016 Aug 8.

No relative expansion of the number of prefrontal neurons in primate and human evolution.

Author information

1
Instituto de Ciências Morfológicas, Universidade Federal do Rio De Janeiro, 21941-901, Rio de Janeiro, Brazil; Instituto Nacional de Neurociência Translacional, 04023-900, Sao Paulo, Brazil; Department of Psychology, Vanderbilt University, Nashville, TN 37240;
2
Instituto de Ciências Morfológicas, Universidade Federal do Rio De Janeiro, 21941-901, Rio de Janeiro, Brazil; Instituto Nacional de Neurociência Translacional, 04023-900, Sao Paulo, Brazil;
3
Universidade Federal de São Paulo, 04021-001, Sao Paulo, Brazil; Museu Paraense Emílio Goeldi, 66040-170, Belem, Brazil;
4
Instituto de Física, Universidade Federal do Rio De Janeiro, 21941-901, Rio de Janeiro, Brazil;
5
Department of Psychology, Vanderbilt University, Nashville, TN 37240; jon.h.kaas@vanderbilt.edu suzana.herculano@vanderbilt.edu.
6
Instituto de Ciências Morfológicas, Universidade Federal do Rio De Janeiro, 21941-901, Rio de Janeiro, Brazil; Instituto Nacional de Neurociência Translacional, 04023-900, Sao Paulo, Brazil; Department of Psychology, Vanderbilt University, Nashville, TN 37240; Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235 jon.h.kaas@vanderbilt.edu suzana.herculano@vanderbilt.edu.

Abstract

Human evolution is widely thought to have involved a particular expansion of prefrontal cortex. This popular notion has recently been challenged, although controversies remain. Here we show that the prefrontal region of both human and nonhuman primates holds about 8% of cortical neurons, with no clear difference across humans and other primates in the distribution of cortical neurons or white matter cells along the anteroposterior axis. Further, we find that the volumes of human prefrontal gray and white matter match the expected volumes for the number of neurons in the gray matter and for the number of other cells in the white matter compared with other primate species. These results indicate that prefrontal cortical expansion in human evolution happened along the same allometric trajectory as for other primate species, without modification of the distribution of neurons across its surface or of the volume of the underlying white matter. We thus propose that the most distinctive feature of the human prefrontal cortex is its absolute number of neurons, not its relative volume.

KEYWORDS:

cortical expansion; evolution; number of neurons; prefrontal cortex; primate

PMID:
27503881
PMCID:
PMC5003225
DOI:
10.1073/pnas.1610178113
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center