Trends in Neurosciences
Volume 21, Issue 2, 1 February 1998, Pages 64-71
Journal home page for Trends in Neurosciences

Cajal–Retzius cells and the development of the neocortex

https://doi.org/10.1016/S0166-2236(97)01164-8Get rights and content
Under a Creative Commons license
open archive

Abstract

The dual origin, structural organization, and evolving ascending stratification of the mammalian neocortex are explored from a developmental perspective. Layer I and subplate (layer VII) zone of the neocortex evolve first from a primordial plexiform neuropil that is established throughout the non-olfactory telencephalon and that is common to amphibians, reptiles and mammals. The remaining laminations (strata) of the neocortex evolve later, between layer I and the subplate zone, from the cortical plate (CP), which represents a multilayered mammalian evolutionary feature. The attraction of CP neurons towards layer I, their progressive ascending (inside-out) placement, common early differentiation stage (regardless of size, location, cortical depth, or eventual functional role, or all of these), and the unique morphologic features of its pyramidal neuron are developmental processes controlled by layer I and its Cajal–Retzius cells. Based on the role of these early neurons and of layer I, a new theory of neocortical cytoarchitectonics and nomenclature is proposed to explain the basic structural and functional organization of the mammalian neocortex, the morphology of its pyramidal cells, and the addition of new pyramidal cell strata that characterize its phylogenetic evolution.

Keywords

layer I
neocortex
development
Cajal-Retzius cell
phlyogeny
onotgeny

Cited by (0)